154: Gram-Negative Coccal and Bacillary Infections Flashcards

Question

What is the primary risk factor for higher infection rates of N. meningitidis in older children?

Answer 1

Close living conditions such as in colleges and dormitories.

Answer 2

A, W-135, X in sub-Saharan Africa; B and C in developed countries; Y associated with meningococcal pneumonia in adults.

Answer 3

Through respiratory droplets, direct contact, or kissing.

Answer 4

Petechial rash, which may progress to fulminant septicemia.

Answer 5

Extremities, but it can occur all over the body including palms, soles, mucous membranes, and conjunctiva.

Answer 6

Disseminated intravascular coagulation (DIC).

Answer 7

Myalgias, arthralgias, cold or discolored extremities, hypotension, altered mental status, renal failure, ARDS, and DIC.

Answer 8

Waterhouse-Friedrichsen syndrome.

Answer 9

It is a positive regulator of the alternative complement pathway, and its deficiency increases the risk of infection.

Answer 10

Key risk factors include: - Lack of bactericidal antibodies due to: - Anatomic/functional asplenia - HIV - Defects of terminal alternative complement pathways - Deficiency of properdin, a positive regulator of the alternative complement pathway.

Answer 11

Acute meningococcemia presents with: - Fever and a petechial rash that can progress to fulminant septicemia within hours. - The petechial rash is a hallmark sign, often small and irregular with a smudged appearance. - It is more common in children aged 1-18 than in infants and adults, and its rapid increase in number and size indicates fulminant disease progression.

Answer 12

| Feature | Acute Meningococcemia | Chronic Meningococcemia | |-----------------------------|------------------------------------------------|--------------------------------------------------| | Rash | Petechial rash, hallmark sign | Polymorphic rash, fades and recurs | | Appearance | Small, irregular, smudged | Rose-colored papules/macules | | Progression | Rapid increase in number and size | Weeks to months of recurrent fevers | | Other findings | Purpura fulminans, skin necrosis | Erythema nodosum-like nodules, petechiae |

Answer 13

Non-cutaneous findings include: - Myalgias and arthralgias - Cold or discolored extremities - Hypotension - Altered mental status - Renal failure - Acute Respiratory Distress Syndrome (ARDS) - Waterhouse-Friedrichsen syndrome, which is characterized by adrenal hemorrhage and can lead to adrenal insufficiency.

Answer 14

Common clinical features include: 1. **Nuchal rigidity** 2. **Headache** 3. **Photophobia** 4. **Fever** 5. **Altered mental status** 6. **Positive Kernig and Brudzinski signs** 7. Potential for septic foci in other locations (e.g., septic arthritis, purulent pericarditis, bacterial endocarditis).

Answer 15

Complications include: 1. **Purpura fulminans** – can lead to amputation. 2. **Meningitis** – may result in sensorineural hearing loss/deafness, seizures, hydrocephalus, mental retardation, and cognitive/behavioral problems. 3. **Chronic meningococcemia** – can lead to acute meningococcemia, meningitis, and carditis.

Answer 16

The gold standard laboratory tests for diagnosing acute meningococcemia include: - **Culture** of: - Blood - CSF (Cerebrospinal fluid) - Synovial fluid - Pleural fluid - Pericardial fluid - Skin biopsy - **PCR** (Polymerase Chain Reaction) if there is high suspicion but negative workup.

Answer 17

**Advantages of PCR:** 1. **Highly sensitive and specific** 2. **Sensitivity not diminished** 3. **Fast results** 4. **More helpful in chronic meningococcemia** due to difficulties in obtaining cultures. **Disadvantages of PCR:** 1. **Cannot determine antibiotic sensitivity** 2. **No widespread availability**

Answer 18

Histopathological findings in chronic meningococcemia include: - **Perivascular infiltrates** of lymphocytes and neutrophils. - **Leukocytoclastic vasculitis** in petechial lesions.

Answer 19

Blood culture (40-80% sensitivity), CSF culture, and PCR for high sensitivity and specificity. Skin biopsy may also be used if antibiotics have already been administered.

Answer 20

Delayed immune complex-mediated syndrome, which occurs during recovery and manifests as sterile arthritis, vasculitis, pleuritis, pericarditis, or episcleritis.

Answer 21

Perform blood culture, PCR for high sensitivity, and skin biopsy to identify perivascular infiltrates of lymphocytes and neutrophils.

Answer 22

PCR, as it is highly sensitive and specific, and its sensitivity is not diminished by prior antibiotic use.

Answer 23

Necrotizing vasculitis, perivascular infiltrates of neutrophils and monocytes, microvascular thrombosis, and perivascular hemorrhage.

Answer 24

Sensorineural hearing loss is the most common sequelae of meningitis, along with seizures, hydrocephalus, and cognitive or behavioral problems.

Answer 25

Meningococcal meningitis can lead to septic foci in other locations, including purulent pericarditis, due to the breach of the blood-brain barrier.

Answer 26

Nuchal rigidity, headache, photophobia, fever, altered mental status, and positive Kernig and Brudzinski signs.

Answer 27

Purpura fulminans.

Answer 28

Meningococcal meningitis can lead to septic foci in other locations, including purulent pericarditis, due to the breach of the blood-brain barrier.

Answer 29

Sensorineural hearing loss, seizures, hydrocephalus, mental retardation, and cognitive behavioral problems.

Answer 30

Culture of blood, CSF, synovial fluid, pleural fluid, pericardial fluid, or skin biopsy.

Answer 31

Highly sensitive and specific, sensitivity not diminished, fast results, and more helpful in chronic meningococcemia.

Answer 32

Cannot determine antibiotic sensitivity and no widespread availability.

Answer 33

Perivascular infiltrates of lymphocytes and neutrophils, and leukocytoclastic vasculitis in petechial lesions.

Answer 34

It occurs while patients are in recovery and manifests as sterile arthritis, vasculitis, pleuritis, pericarditis, and episcleritis.

Answer 35

Clinical features include nuchal rigidity, headache, photophobia, fever, altered mental status, and positive Kernig and Brudzinski signs. These symptoms arise due to inflammation and irritation of the meninges, which can occur when the blood-brain barrier is breached.

Answer 36

Potential complications include purpura fulminans, sensorineural hearing loss, seizures, hydrocephalus, and chronic meningococcemia. These highlight the importance of early diagnosis and treatment to prevent long-term morbidity.

Answer 37

Advantages include high sensitivity and specificity, sensitivity not diminished after antibiotic initiation, fast results, and usefulness in chronic meningococcemia. Disadvantages include inability to determine antibiotic sensitivity and limited availability.

Answer 38

Necrotizing vasculitis, gram-negative cocci on gram stain, and perivascular infiltrates of lymphocytes and neutrophils.

Answer 39

Early initiation of antibiotics (not less than 30 minutes between diagnosis and administration of IV antibiotics).

Answer 40

The standard antibiotic duration is 7 days.

Answer 41

Third generation cephalosporins (Ceftriaxone, Cefotaxime) are recommended for empiric treatment.

Answer 42

The conjugate quadrivalent vaccine is recommended, with a booster at 12-16 years old.

Answer 43

It is recommended for certain high-risk patients over 10 years old and for elective administration in patients aged 16-23 years, preferably between 16-18 years.

Answer 44

Early initiation of IV antibiotics (e.g., third-generation cephalosporins) and administration of Protein C concentrate.

Answer 45

Administer the conjugate quadrivalent vaccine at 11-12 years old with a booster at 16 years old. If the first dose is given after 16 years, a booster is not needed.

Answer 46

Early initiation of antibiotics (within 30 minutes of diagnosis) is the single most important factor in the treatment of meningococcemia, as it significantly improves patient outcomes and reduces the risk of severe complications.

Answer 47

The standard antibiotic treatment for acute meningococcemia is a duration of 7 days, typically involving third generation cephalosporins, Penicillin G or Ampicillin if MIC is <0.1 µg/mL, Chloramphenicol if there is an allergy, and Protein C concentrate for purpura fulminans.

Answer 48

Vaccination recommendations include the conjugate quadrivalent vaccine for patients aged 11-12 years with a booster at 12-16 years, and the serogroup B meningococcal vaccine for high-risk patients over 10 years old.

Answer 49

Close contact is defined as prolonged contact >8 hours, close proximity <3 feet, and direct exposure to patients' oral secretions from 7 days before symptom onset until 24 hours following initiation of treatment.

Answer 50

The recommended antibiotics for prophylaxis are Rifampin (4 doses over 2 days), Ciprofloxacin (single dose), and Ceftriaxone (single IM dose; use in pregnancy).

Answer 51

Acute meningococcal infection is often fatal, leading to shock and multiple organ failure.

Answer 52

Without treatment, chronic meningococcemia is more likely to worsen and progress to affect vital function, leading to death. However, if treated, the prognosis is excellent.

Answer 53

Within 24 hours of identification of the index patient.

Answer 54

The criteria for defining close contact include prolonged contact >8 hours, close proximity <3 feet, and direct exposure to patients' oral secretions from 7 days before symptom onset until 24 hours following initiation of treatment.

Answer 55

The treatment options include Rifampin (4 doses over 2 days), Ciprofloxacin (single dose), and Ceftriaxone (single IM dose; use in pregnancy).

Answer 56

Acute meningococcal infection can be fatal, leading to shock and multiple organ failure if left untreated.

Answer 57

Without treatment, chronic meningococcemia is more likely to worsen and progress to affect vital function, leading to death. If treated, the prognosis is excellent, with some patients spontaneously recovering.

Answer 58

Gram-negative rod with a sweet, grape-like odor and blue-green color due to pyocyanin pigment. Oxidase positive, non-lactose fermenting, and obligately aerobic.

Answer 59

Green nail syndrome, toe web infection, folliculitis, hot-foot syndrome, external otitis, and perichondritis.

Answer 60

ExoS, ExoT, ExoU, ExoY, Exotoxin A, Lipooligosaccharide, Pyocyanin, Pyoverdin & Pyochelin, and Alginate.

Answer 61

Biofilms, efflux pumps, beta-lactamases, and porin downregulation.

Answer 62

Pseudomonas aeruginosa, which produces pyocyanin and pyoverdin pigments.

Answer 63

A ubiquitous Gram-negative rod.

Answer 64

Blue-green color and grape-like odor.

Answer 65

Nosocomial pneumonia, cystic fibrosis lung infections, and skin infections.

Answer 66

They interact with TLRs to induce TNF-a production and damage host tissues.

Answer 67

It is a pigment specific to Pseudomonas and contributes to its pathogenicity.

Answer 68

It can cause severe infections, especially in immunocompromised hosts, with high mortality rates.

Answer 69

A breach in skin integrity is typically required for invasion.

Answer 70

Skin integrity is necessary for invasion and infection.

Answer 71

Primary cutaneous infections include: - Green nail syndrome - Toe web infection - Folliculitis - Hot-foot syndrome - External otitis - Perichondritis

Answer 72

Conditions that necessitate a breach in skin integrity include: - Trauma or burns - Indwelling catheters - Maceration of skin - Dermatophyte infections

Answer 73

Answer 74

These factors enhance the bacterium's ability to invade tissues, evade the immune system, and establish persistent infections.

Answer 75

Answer 76

Actively expel antibiotics from bacterial cells.

Answer 77

Enzymes that degrade beta-lactam antibiotics.

Answer 78

Reduces permeability of the outer membrane to antibiotics.

Answer 79

They complicate treatment options and necessitate the use of combination therapies or alternative antibiotics.

Answer 80

1. **Conjunctival microflora** 2. **Feces of healthy patients** 3. **Water reservoir systems**

Answer 81

1. **Prolonged submersion** in fresh water, soap, and detergents 2. **Onycholysis** 3. **Chronic paronychia** 4. **Nail disorders**

Answer 82

1. **Recreational use of hot tubs, whirlpools, or pools** that lack adequate halogenation 2. **Heated water** above 38 degrees, with increased infection risk correlating with the duration of bathing.

Answer 83

1. **Lungs** 2. **Urinary tract** 3. **Gastrointestinal tract** 4. **Skin and soft tissues (wound infection)**

Answer 84

Risk factors include conditions that compromise the immune system or skin integrity.

Answer 85

1. Swimmers 2. Excessive ear scratching/cleaning 3. Ear occluding devices 4. Presence of dermatologic conditions that promote breakdown of skin cerumen barrier 5. Microangiopathy of ear canal 6. Increased pH of diabetic cerumen

Answer 86

Pseudomonas aeruginosa, which is frequently isolated from burn wounds.

Answer 87

Pseudomonas aeruginosa, the third most common cause of catheter-associated UTIs.

Answer 88

Pseudomonas aeruginosa. Risk factors include hospitalization, neutropenia, hematologic malignancy, and recent antibiotic use.

Answer 89

Conjunctival microflora and feces of healthy patients, and water reservoir systems.

Answer 90

Pseudomonas aeruginosa.

Answer 91

Prolonged submersion in fresh water, soap, and detergents; onycholysis, chronic paronychia, nail disorders.

Answer 92

Chronic paronychia is a nail disorder.

Answer 93

Persistently wet feet, closed toe shoes, tight fitting shoes, occupational or recreational exertion, and/or warm humid weather.

Answer 94

Recreational use of hot tubs, whirlpools, and heated water above 38 degrees.

Answer 95

Swimmers, excessive ear scratching/cleaning, ear occluding devices, and presence of dermatologic conditions.

Answer 96

Pseudomonas and Aspergillus.

Answer 97

Lungs, urinary tract, gastrointestinal tract, skin, and soft tissues (wound infection).

Answer 98

Hospitalization, neutropenia, hematologic malignancy, CD4 < 50, immunocompromised status, recent courses of antibiotics/chemo, and invasive devices.

Answer 99

Green nail syndrome develops due to prolonged submersion in fresh water, soap, and detergents. The primary risk factors include: 1. Onycholysis 2. Chronic paronychia 3. Nail disorders.

Answer 100

Toe web infections are commonly associated with the following risk factors: 1. Persistently wet feet 2. Closed toe shoes 3. Tight fitting shoes 4. Occupational or recreational exertion in warm humid weather. **Prevention strategies** include: - Keeping feet dry - Wearing breathable footwear - Avoiding prolonged exposure to wet conditions.

Answer 101

The risk of folliculitis and hot foot syndrome increases due to: 1. Recreational use of hot tubs, whirlpools, and pools lacking adequate halogenation. 2. Bathing in heated water above 38 degrees Celsius. 3. Prolonged duration of bathing.

Answer 102

Prevention includes ensuring proper water sanitation and limiting time spent in hot water.

Answer 103

Malignant otitis externa is characterized by: 1. Invasion of soft tissues at the cartilaginous junction of the external auditory canal. 2. Risk factors include: - Microangiopathy of the ear canal. - Increased pH of diabetic cerumen. - Common in elderly and immunocompromised individuals.

Answer 104

Common causative agents include: - Pseudomonas aeruginosa. - Aspergillus species.

Answer 105

In bacteremia associated with Pseudomonas aeruginosa, the primary sites of infection include: 1. Lungs. 2. Urinary tract. 3. Gastrointestinal tract. 4. Skin and soft tissues (wound infections).

Answer 106

Risk factors for developing bacteremia include: - Hospitalization. - Neutropenia. - Hematologic malignancy. - CD4 count < 50. - Immunocompromised status. - Recent courses of antibiotics or chemotherapy. - Use of invasive devices.

Answer 107

Nail dyspigmentation: Greenish-yellow/brown/black due to accumulation of debris.

Answer 108

A condition characterized by greenish-yellow/brown/black due to accumulation of debris and pyocyanin.

Answer 109

Typically limited to one or two digits; may affect the entire or partial nail.

Answer 110

Dyspigmentation, Onycholysis, Paronychia.

Answer 111

1. Green nail syndrome 2. Toe web infection 3. Folliculitis 4. Hot foot syndrome 5. External otitis 6. Perichondritis

Answer 112

Appearance: Thickened, macerated skin with a characteristic moth-eaten appearance and yellow-green pustules. ## Footnote Affected areas: Affects the toe web spaces and sole of the foot; may be accompanied by burning and pain.

Answer 113

Common in children. Symptoms: Acute painful erythematous, warm, plantar nodules after immersion in contaminated wading pools or hot tubs.

Answer 114

Onset: Acute onset of edema and erythema or discoloration of the external auditory canal (EAC) sometimes with maceration, discharge, and regional lymphadenopathy (LAD). ## Footnote Symptoms: (+) tragal tenderness, pruritus. Most common in children aged 5-14 years.

Answer 115

Onset: Insidious onset with edema, erythema, and persistent discharge from the ear canal. ## Footnote Pain: Severe pain disproportionate to examination findings. Risk groups: More common in elderly patients and diabetics.

Answer 116

Life-threatening; can lead to skull base osteomyelitis.

Answer 117

Malignant otitis externa, which involves soft tissue invasion and can lead to skull base osteomyelitis.

Answer 118

Hot tub folliculitis caused by Pseudomonas aeruginosa, typically presenting 24 hours after exposure.

Answer 119

Hot foot syndrome caused by Pseudomonas aeruginosa, commonly seen in children.

Answer 120

External otitis (swimmer's ear) caused by Pseudomonas aeruginosa.

Answer 121

Malignant otitis externa caused by Pseudomonas aeruginosa, often following water irrigation in diabetic or immunocompromised patients.

Answer 122

Hot tub folliculitis caused by Pseudomonas aeruginosa.

Answer 123

Hot foot syndrome caused by Pseudomonas aeruginosa.

Answer 124

External otitis (swimmer's ear) caused by Pseudomonas aeruginosa.

Answer 125

External otitis (swimmer's ear) caused by Pseudomonas aeruginosa.

Answer 126

Green nail syndrome.

Answer 127

Toe web infection.

Answer 128

24 hours following exposure to contaminated hot tubs.

Answer 129

Acute onset of edema, erythema, and discharge from the ear canal.

Answer 130

Dyspigmentation, Onycholysis, Paronychia.

Answer 131

Skull base osteomyelitis.

Answer 132

Localized skin infections in immunocompetent patients.

Answer 133

Acute painful erythematous, warm, plantar nodules after immersion in contaminated water.

Answer 134

**Green nail syndrome** is characterized by: - **Nail dyspigmentation**: greenish-yellow/brown/black due to debris and pyocyanin accumulation. - Typically affects **one or two digits**, but can involve the entire or partial nail. - **Triad of symptoms**: Dyspigmentation, Onycholysis, Paronychia.

Answer 135

**Folliculitis** is characterized by inflammation of hair follicles, often caused by bacteria or fungi, particularly in warm, moist environments like hot tubs.

Answer 136

Hot tub folliculitis presents with discrete follicular papules and pustules that heal with fine desquamation and hyperpigmented macules.

Answer 137

Sudden onset occurring 24 hours after exposure to contaminated hot tubs, often associated with pruritus or pain.

Answer 138

Commonly affects areas covered by bathing suits, such as the upper trunk, axillary folds, hips, and buttocks.

Answer 139

External otitis/Swimmer's ear is characterized by acute onset of edema and erythema or discoloration of the external auditory canal (EAC), sometimes with maceration and discharge.

Answer 140

Symptoms include tragal tenderness and pruritus.

Answer 141

Most common in children aged 5-14 years.

Answer 142

Malignant otitis externa can occur, presenting with: 1. Insidious onset with severe pain disproportionate to examination findings. 2. Higher risk in elderly patients and diabetics. 3. Can be life-threatening, leading to skull base osteomyelitis.

Answer 143

Localized skin infections in immunocompetent patients can become a source of bacteremia in immunocompromised patients. This highlights the importance of early identification and management of skin infections to prevent potential systemic complications, especially in vulnerable populations.

Answer 144

Classic findings include granulatin tissue.

Answer 145

**Granulation tissue** in the floor of the external auditory canal (EAC) and **bony cartilaginous junction** blocking the tympanic membrane (TM).

Answer 146

SQ nodules are **warm**, **erythematous**, **indurated**, usually **non-fluctuant**, and can be **painful or less painful**. They typically affect the **face, neck, chest, abdomen, back, and extremities**.

Answer 147

Ecthyma gangrenosum begins as a **painless**, infarcted **gunmetal gray macule** or papule with surrounding **erythema**. It becomes **indurated**, and **hemorrhagic bullae** may develop. Over 12-18 hours, it progresses to a **necrotic**, **ulcerative eschar** with a halo of **tender erythema**. Common locations include **anogenital, extremities, trunk, and face**.

Answer 148

Non-cutaneous findings include **fever and malaise**, even in the absence of bacteremia or mild infections, and **sepsis** with systemic symptoms. Additionally, otitis externa (OE) may lead to **conductive hearing loss** and **cranial nerve palsies** (most commonly the facial nerve), as well as **trismus** and **lockjaw**.

Answer 149

For diagnosing perichondritis, **otoscopy** and **cultures** should be performed. Additionally, perichondritis should be cultured following incision and drainage (I and D).

Answer 150

**CT/MRI** is used to assess malignant otitis externa (OE) to evaluate the extent of the disease.

Answer 151

CT/MRI is used to detect extension into the **bony structures** in cases of malignant otitis externa (OE). It helps differentiate from other conditions, such as **squamous cell carcinoma (SCC)**.

Answer 152

Histopathological findings in hot foot syndrome include **perivascular, interstitial, and peri-adnexal neutrophils** that extend to the lobules of subcutaneous fat and may include **deep dermal or subcutaneous abscess**.

Answer 153

Ecthyma gangrenosum caused by Pseudomonas aeruginosa, commonly seen in neutropenic patients.

Answer 154

Bacteremia with ecthyma gangrenosum caused by.

Answer 155

Perichondritis caused by Pseudomonas aeruginosa, often following trauma or contaminated cleaning agents.

Answer 156

Bacteremia with subcutaneous nodules caused by Pseudomonas aeruginosa, commonly seen in immunocompromised patients.

Answer 157

Ecthyma gangrenosum caused by Pseudomonas aeruginosa, commonly seen in neutropenic patients.

Answer 158

Ecthyma gangrenosum caused by Pseudomonas aeruginosa.

Answer 159

Bacteremia with ecthyma gangrenosum caused by Pseudomonas aeruginosa.

Answer 160

Infections caused by Pseudomonas aeruginosa.

Answer 161

Granulation tissue in the floor of EAC and bony cartilaginous junction blocking the tympanic membrane (TM).

Answer 162

An infection following commercial piercings due to contaminated cleansing agents, trauma, or acupuncture, leading to rapid cartilage necrosis.

Answer 163

Warm, erythematous, indurated, usually non-fluctuant, and painful/less, affecting the face, neck, chest, abdomen, back, and extremities.

Answer 164

Necrotic lesions associated with P. aeruginosa bacteremia, beginning as a painless, infarcted gray macule or papule with surrounding erythema, which can develop into a necrotic ulcerative eschar.

Answer 165

Fever and malaise, sepsis with systemic symptoms, and conductive hearing loss with cranial nerve palsies.

Answer 166

Unroofing and culture of pustules and bacterial subtyping.

Answer 167

CT/MRI to detect extension into the bony structures; differential diagnosis includes squamous cell carcinoma (SCC).

Answer 168

Perivascular, interstitial, and peri-adnexal neutrophils extending to the lobules of subcutaneous fat, possibly including deep dermal or subcutaneous abscess.

Answer 169

Clinical features of SQ are not specified in the provided text.

Answer 170

SQ nodules are characterized by: - Warm, erythematous, indurated, usually non-fluctuant - Painful or less painful - Commonly affect the face, neck, chest, abdomen, back, and extremities.

Answer 171

Ecthyma gangrenosum begins as: 1. A painless, infarcted gunmetal gray macule or papule with surrounding erythema. 2. It becomes indurated, and hemorrhagic bullae may develop. 3. Over 12-18 hours, it progresses to a necrotic, ulcerative eschar with a halo of tender erythema.

Answer 172

Non-cutaneous findings in bacteremia may include: - Fever and malaise, even in the absence of bacteremia or mild infections. - Sepsis with systemic symptoms. - Otitis externa (OE) leading to conductive hearing loss and cranial nerve palsies, particularly affecting the facial nerve, as well as trismus and lockjaw.

Answer 173

For diagnosing Pseudomonal folliculitis, the following laboratory tests are recommended: 1. Unroofing and culture of pustules for bacterial subtyping. 2. Hot foot syndrome may require a punch biopsy for histopathology and culture.

Answer 174

Imaging techniques for assessing malignant otitis externa include: - CT or MRI, which are used to detect extension into the bone.

Answer 175

CT or MRI.

Answer 176

Differential diagnosis may include squamous cell carcinoma (SCC).

Answer 177

The primary drug treatments include: | Class of Drug | Examples | |---------------|----------| | Penicillins | Ticarcillin-Clavulanic, Pip-tazo | | Cephalosporins | Cefepime, Ceftazidime, Cefoperazone | | Monobactams | Aztreonam | | Carbapenems | Meropenem, Doripenem, Imipenem-cilastatin | | Fluoroquinolones | Ciprofloxacin, Levofloxacin | | Aminoglycosides | Gentamicin, Tobramycin, Amikacin | | Polymyxin | Colistin |

Answer 178

The management approach includes: 1. Removal of the detached nail plate. 2. Application of topical antimicrobial for 1-4 months while avoiding chronic moisture or water submersion. 3. Antimicrobials that can be used include: - Sodium hypochlorite 2% - Aminoglycosides (Tobramycin, Gentamicin) - Fluoroquinolones (Ciprofloxacin, Nadifloxacin) - Polymyxin B - Bacitracin - Acetic acid.

Answer 179

The treatment options include: 1. Require both antibacterial and antifungal therapy + necrotic tissue debridement. 2. For mild cases: topical gentamicin. 3. For fulminant cases: oral antibiotics (Ciprofloxacin).

Answer 180

The recommended treatment includes: 1. Prompt referral to surgical ENT service for debridement of necrotic tissue and possible mastoidectomy if extensive. 2. A prolonged course of systemic antibiotics: - Ciprofloxacin for 6-8 weeks for sensitive strains. - Anti-pseudomonal beta lactam (Pip-tazo, ceftazidime, cefepime) for fluoroquinolone resistant strains.

Answer 181

Ecthyma gangrenosum is characterized by: - Acute vasculitis and suppurative panniculitis with visible gram-negative rods. - It indicates necrotizing Gram-negative bacteria affecting small vessels, which can lead to severe systemic infections, particularly in immunocompromised patients.

Answer 182

Green nail syndrome caused by Pseudomonas aeruginosa. Treatment includes removal of the detached nail plate and application of topical antimicrobials like sodium hypochlorite or aminoglycosides.

Answer 183

Pseudomonal toe web infection. Treatment includes antibacterial and antifungal therapy, necrotic tissue debridement, and topical or oral antibiotics.

Answer 184

IV treatment.

Answer 185

Ciprofloxacin.

Answer 186

Castellani (Carbol-fuchsin) paint, Gentian violet, and acetic acid soaks.

Answer 187

Green nail syndrome caused by Pseudomonas aeruginosa. Treatment includes topical antimicrobials and avoidance of moisture.

Answer 188

Malignant otitis externa caused by Pseudomonas aeruginosa. Treatment includes systemic antibiotics like ciprofloxacin or anti-pseudomonal beta-lactams.

Answer 189

Pseudomonal toe web infection. Treatment includes antibacterial and antifungal therapy, along with necrotic tissue debridement.

Answer 190

Drug treatment includes Penicillins, Cephalosporins, Carbapenems, Fluoroquinolones, Aminoglycosides, and Polymyxin.

Answer 191

Removal of detached nail plate followed by topical antimicrobial application for 1-4 months, avoiding chronic moisture or water submersion.

Answer 192

Requires both antibacterial and antifungal therapy along with necrotic tissue debridement.

Answer 193

Self-limited; exposure removal and symptomatic care, with oral ciprofloxacin for protracted cases.

Answer 194

Treatment details not provided.

Answer 195

Prompt referral to surgical ENT service for debridement and a prolonged course of systemic antibiotics.

Answer 196

Resistance can develop to Imipenem-Cilastatin and Ciprofloxacin.

Answer 197

Treatment involves systemic antibiotics and addressing the underlying infection.

Answer 198

The drug treatment includes: - Penicillins: Ticarcillin-Clavulanic, Pip-tazo - Cephalosporins: Cefepime, Ceftazidime, Cefoperazone - Monobactams: Aztreonam - Carbapenems: Meropenem, Doripenem, Imipenem-cilastatin - Fluoroquinolones: Ciprofloxacin, Levofloxacin - Aminoglycosides: Gentamicin, Tobramycin, Amikacin - Polymyxin: Colistin

Answer 199

The management includes: 1. Removal of the detached nail plate. 2. Application of topical antimicrobials for 1-4 months while avoiding chronic moisture or water submersion. ## Footnote Topical agents may include: - Sodium hypochlorite 2% - Aminoglycosides (Tobramycin, Gentamicin) - Fluoroquinolones (Ciprofloxacin, Nadifloxacin) - Polymyxin B - Bacitracin - Acetic acid

Answer 200

Treatment varies based on severity: | Severity Level | Treatment | |----------------|-----------| | Mild cases | Topical gentamicin | | Full cases | Systemic antibiotics |

Answer 201

Topical gentamicin.

Answer 202

Oral antibiotics (Ciprofloxacin).

Answer 203

IV treatment.

Answer 204

Necrotic tissue debridement and antifungal therapy are required, along with the use of Castellani paint, Gentian violet, and acetic acid soaks.

Answer 205

1. Prompt referral to surgical ENT service for debridement of necrotic tissue and possible mastoidectomy if extensive. 2. Prolonged course of systemic antibiotics: - Ciprofloxacin for 6-8 weeks for sensitive strains. - Anti-pseudomonal beta-lactam (Pip-tazo, Ceftazidime, Cefepime) for fluoroquinolone-resistant strains.

Answer 206

Ecthyma gangrenosum is a significant clinical manifestation often associated with bacteremia, particularly in immunocompromised patients. It presents as necrotizing Gram-negative bacterial infections that can lead to severe skin lesions and systemic infection, indicating a need for prompt diagnosis and aggressive treatment to prevent further complications.

Answer 207

Prompt IV empiric therapy with **anti-pseudomonal beta-lactam** should be initiated, addressing the primary site of infection.

Answer 208

Both conditions are **benign and self-limiting**, improving rapidly with topical and oral therapy.

Answer 209

Malignant otitis is invasive and has a high mortality rate.

Answer 210

Bacteremia caused by Pseudomonas aeruginosa is associated with higher mortality than that caused by other gram-negative organisms.

Answer 211

Combination therapy should be used, including the addition of aminoglycosides, but aminoglycosides should never be used as monotherapy when other options are available.

Answer 212

Prompt IV empiric therapy with anti-pseudomonal beta-lactam.

Answer 213

Combination therapy with aminoglycosides.

Answer 214

Because other options should be available and they are not effective alone.

Answer 215

They are benign and self-limiting, improving rapidly with topical and oral therapy.

Answer 216

It is associated with higher mortality.

Answer 217

Prompt IV empiric therapy with anti-pseudomonal beta-lactam.

Answer 218

The primary site of infection is often in cases of neutropenia with signs of sepsis.

Answer 219

Prompt IV empiric therapy with anti-pseudomonal beta-lactam should be initiated.

Answer 220

Combination therapy should include an anti-pseudomonal beta-lactam and an aminoglycoside, as aminoglycosides should never be used as monotherapy when other options are available.

Answer 221

Both conditions are benign and self-limited, improving rapidly with topical and oral therapy.

Answer 222

The mortality rate for malignant otitis is approximately 20%.

Answer 223

Bacteremia caused by Pseudomonas aeruginosa is associated with higher mortality than that caused by other gram-negative organisms.

Answer 224

1. Bartonella henselae: Cat Scratch Disease (CSD), Bacillary Angiomatosis (BA), Endocarditis. 2. Bartonella quintana: Trench Fever, BA, Endocarditis. 3. Bartonella bacilliformis: Carrion Disease (Oroya fever and verruga peruana).

Answer 225

Cat flea (Ctenocephalides felis).

Answer 226

Human body louse (Pediculus humanus).

Answer 227

Sand fly (Lutzomyia verrucarum).

Answer 228

Bartonella employs several mechanisms: Weak Recognition by TLR4, Antigenic Variation, Parasitizing Host Erythrocytes, and Affinity for Endothelial Cells.

Answer 229

Bartonella contributes to the formation of angiomatous lesions through increased cell migration and secretion of Vascular Endothelial Growth Factor (VEGF).

Answer 230

CSD is the most common Bartonella infection, more prevalent in warm, humid climates, peaks in fall and winter, primarily affects immunocompetent patients with a median age of 15 years, and is associated with a history of cat contact.

Answer 231

Cat Scratch Disease (CSD), Bacillary Angiomatosis (BA), and Endocarditis.

Answer 232

Cats are the main reservoir for the causative agent.

Answer 233

Fall and winter.

Answer 234

A median age of 15 years.

Answer 235

It helps to subvert adaptive immunity.

Answer 236

Erythematous papule at the inoculation site, regional lymphadenomegaly, and Parinaud oculoglandular syndrome.

Answer 237

Fever, chills, malaise, headache, weight loss, nausea, vomiting, or splenomegaly.

Answer 238

Inoculation-site lesions typically persist for 1-3 weeks, cutaneous manifestations heal without scarring, and lymphadenitis is usually benign and self-limited.

Answer 239

CSD is generally benign and self-limited; no treatment is recommended for mild to moderate disease.

Answer 240

90% of patients may develop crops of erythematous macules or papules across the abdomen, chest, and back.

Answer 241

Sudden-onset febrile episodes lasting approximately 5 days, chills, malaise, anorexia, and muscle aches.

Answer 242

The etiologic agent is B. quintana, and the vector is the human body louse (P. humanus).

Answer 243

Indirect fluorescent antibody (IFA) assay, lymph node biopsy for histology, Warthin-Starry staining, and PCR on lymph node aspirates.

Answer 244

No treatment is recommended for mild to moderate disease; for large lymphadenopathy, azithromycin, doxycycline, and erythromycin may be used.

Answer 245

CSD may present with abdominal pain, weight loss, and tenderness of the liver/spleen, with mildly abnormal liver function tests, elevated ESR, and CRP.

Answer 246

Inoculation-site lesions typically persist for 1-3 weeks. Cutaneous manifestations generally heal without scarring. Lymphadenitis is usually benign and self-limited, but disseminated manifestations can be life-threatening. Lymphadenopathy resolves in a median of 7 weeks.

Answer 247

For large, bulky lymphadenopathy, treatment options include: 1. Azithromycin 2. Doxycycline 3. Erythromycin. If lymph nodes suppurate, consider: 1. Needle aspiration 2. Surgical removal. If liver and/or spleen involvement is present, use rifampicin alone or in combination with gentamicin or trimethoprim-sulfamethoxazole.

Answer 248

90% of patients may develop crops of erythematous macules or papules across the abdomen, chest, and back. 5-20 days following exposure, patients may experience cyclic fevers lasting approximately 5 days. Trench Fever is also known as 5-day fever, quintan fever, shinbone fever, and His-Werner disease.

Answer 249

Sudden-onset febrile episodes lasting approximately 5 days. Symptoms may include: chills, malaise, anorexia or diaphoresis, retroorbital pain, headache, muscle aches, joint pain, or shin pain, conjunctival injection, and splenomegaly.

Answer 250

Diagnostic tests include indirect fluorescent antibody (IFA) assay, lymph node biopsy for histology, Warthin-Starry staining, and PCR. Findings may include stellate necrosis surrounded by histiocytes and neutrophils, and bacilli visible on Warthin-Starry stain.

Answer 251

The diagnosis is Cat Scratch Disease (CSD). Imaging findings may include scattered hypodense areas in the liver or spleen on abdominal CT, which are hypoechoic on ultrasonography.

Answer 252

The diagnosis is CSD neuroretinitis. The pathophysiology involves Bartonella henselae causing optic nerve edema and inflammation, leading to hemorrhages, cotton wool spots, and a macular star.

Answer 253

3-10 days: Erythematous papule at the inoculation site, which may become vesicular and crusted (2-6 mm). 3-50 days: Regional lymphadenomegaly, typically affecting axillary, cervical, inguinal, epitrochlear, or preauricular nodes. Lymphadenitis is typically the presenting sign. Parinaud oculoglandular syndrome: Unilateral granulomatous conjunctivitis with ipsilateral preauricular and submandibular lymphadenopathy if the inoculation site is near the eye. Other findings: Morbilliform eruptions, urticaria, erythema nodosum, erythema multiforme, and erythema marginatum.

Answer 254

Fever, abdominal pain, and weight loss. Liver/Spleen may be enlarged and tender; liver function tests may be mildly abnormal. Elevated ESR and CRP indicate inflammation. Atypical manifestations may include granulomatous hepatitis or splenitis, neuroretinitis, encephalitis, myelitis, peripheral neuropathy, facial nerve palsy, arthritis, osteomyelitis, mediastinal masses, and atypical pneumonia.

Answer 255

Azithromycin, Doxycycline, Erythromycin. If lymph nodes suppurate: needle aspiration or surgical removal. If liver and/or spleen involvement: rifampicin alone or in combination with gentamicin or trimethoprim-sulfamethoxazole.

Answer 256

90% of patients may develop crops of erythematous macules or papules across the abdomen, chest, and back. 5-20 days following exposure: Known as trench fever, also referred to as 5-day fever, quintan fever, shinbone fever, and His-Werner disease. Cyclic fevers lasting approximately 5 days.

Answer 257

Sudden-onset febrile episodes lasting approximately 5 days. Symptoms include chills, malaise, anorexia, diaphoresis, retroorbital pain, headache, muscle aches, joint pain, or shin pain. Conjunctival injection and splenomegaly may also occur.

Answer 258

Trench Fever typically follows a mild course, and death is rare.

Answer 259

The characteristic cutaneous lesion is a reddish-purple, angiomatous papule approximately 1 cm in diameter, which may be nodular or pedunculated. The surface can be smooth or verrucous and may ulcerate and occasionally bleed. Less common variants include subcutaneous nodules and hyperkeratotic plaques.

Answer 260

Typical non-cutaneous findings include: 1. Peliosis hepatis: Abdominal pain, hepatomegaly, splenomegaly, elevated alkaline phosphatase and normal or slightly elevated bilirubin and aminotransferases. 2. Splenic peliosis: Thrombocytopenia and pancytopenia. 3. Bone and lymph nodes: Painful, isolated, lytic lesions, radius or tibia are the most commonly affected sites.

Answer 261

Bacillary Angiomatosis is diagnosed via skin biopsy, which is sent for histology, Warthin-Starry staining, and PCR. Additionally, IFA may be used, and BA lesions associated with peliosis hepatis and splenic peliosis may be biopsied.

Answer 262

The management for uncomplicated Bacillary Angiomatosis includes: 1. Erythromycin or doxycycline for 3 or more months. 2. Alternatives include Azithromycin and clarithromycin. 3. Severe cases may require combination therapy with erythromycin or doxycycline plus a rifamycin, and intravenous therapy may be needed initially.

Answer 263

Imaging findings in patients with peliosis hepatis may include: Abdominal CT showing organomegaly and scattered hypodense lesions. Radiographs may reveal lytic lesions with cortical destruction and periosteal reaction. Technetium scans demonstrate increased uptake.

Answer 264

Trench Fever is diagnosed by isolating B. quintana from the blood or using an IFA assay. Management includes 28 days of oral doxycycline plus 14 days of IV gentamicin, or a 4-6 week course of oral doxycycline, erythromycin, or azithromycin for uncomplicated cases.

Answer 265

Cutaneous findings include reddish-purple angiomatous papules, nodules, or plaques that may ulcerate or bleed. Non-cutaneous findings include extracutaneous angiomatous proliferation in the liver, spleen, bones, or lymph nodes, causing symptoms like abdominal pain, hepatosplenomegaly, and lytic bone lesions.

Answer 266

Isolating B. quintana from the blood.

Answer 267

It follows a mild course and death is rare.

Answer 268

28 days of oral doxycycline plus 14 days of IV gentamicin or a 4- to 6-week course of oral doxycycline, erythromycin, or azithromycin.

Answer 269

B. henselae.

Answer 270

Reddish-purple, angiomatous papules approximately 1 cm in diameter that may be nodular or pedunculated.

Answer 271

Peliosis hepatis, splenic peliosis, and painful, isolated, lytic lesions in bones and lymph nodes.

Answer 272

Organomegaly and scattered hypodense lesions on abdominal CT.

Answer 273

Culture-negative endocarditis, especially in those with underlying heart valve abnormalities.

Answer 274

Combination therapy with erythromycin or doxycycline plus a rifamycin, and intravenous therapy may be required.

Answer 275

It may identify bacilli in tissue samples.

Answer 276

The recommended management for uncomplicated Bacillary Angiomatosis includes: 1. Erythromycin or doxycycline for 3 or more months. 2. Alternatives include azithromycin and clarithromycin. 3. Severe cases may require combination therapy with erythromycin or doxycycline plus a rifamycin, and intravenous therapy may be needed initially.

Answer 277

The typical cutaneous findings associated with Bacillary Angiomatosis include: Characteristic lesion: reddish-purple, angiomatous papule approximately 1 cm in diameter. Lesion may be nodular or pedunculated. Surface is smooth or verrucous and may ulcerate and occasionally bleed. Less common variants include subcutaneous nodules and hyperkeratotic plaques. May also affect the mucosa, and oral lesions have been reported.

Answer 278

The laboratory tests used to diagnose Bacillary Angiomatosis include: 1. Skin biopsy for histology, Warthin-Starry staining, and PCR. 2. IFA (Immunofluorescence Assay) may also be used. 3. BA lesions associated with peliosis hepatis and splenic peliosis may be biopsied for further evaluation.

Answer 279

The non-cutaneous findings associated with Bacillary Angiomatosis may include: Peliosis hepatis: Symptoms: abdominal pain, hepatomegaly, splenomegaly. Laboratory findings: elevated alkaline phosphatase and normal or slightly elevated bilirubin and aminotransferases. Splenic peliosis: Symptoms: thrombocytopenia and pancytopenia. Bone and lymph nodes: Symptoms: painful, isolated, lytic lesions, commonly affecting the radius or tibia.

Answer 280

Imaging findings associated with peliosis hepatis in patients with Bacillary Angiomatosis include: Abdominal CT: shows organomegaly and scattered hypodense lesions. Radiographs: may reveal lytic lesions with cortical destruction and periosteal reaction in patients with bony involvement. Technetium scans: demonstrate increased uptake in affected areas.

Answer 281

The likely diagnosis is Trench Fever caused by B. quintana. Confirmation involves isolating B. quintana from the blood or using an IFA assay.

Answer 282

The likely diagnosis is Bacillary Angiomatosis. Additional tests include skin biopsy for histology, Warthin-Starry staining, PCR, and imaging like abdominal CT to check for peliosis hepatis or splenic peliosis.

Answer 283

The diagnosis is Trench Fever. Pathogenesis involves B. quintana being transmitted via human body lice, leading to bacteremia and cyclic fevers.

Answer 284

The diagnosis is Bacillary Angiomatosis. Confirmation involves skin biopsy, Warthin-Starry staining, PCR, and imaging like radiographs or technetium scans for bone involvement.

Answer 285

The likely diagnosis is Trench Fever. Treatment includes 28 days of oral doxycycline plus 14 days of IV gentamicin, or a 4-6 week course of oral doxycycline, erythromycin, or azithromycin for uncomplicated cases.

Answer 286

The diagnosis is Bacillary Angiomatosis. Management involves erythromycin or doxycycline for 3 or more months, with combination therapy for severe cases.

Answer 287

The diagnosis is Bacillary Angiomatosis. Treatment involves erythromycin or doxycycline for 3 or more months, with combination therapy for severe cases.

Answer 288

The vector for Trench Fever is the human body louse (Pediculus humanus). Transmission occurs via louse feces inoculated into the skin through scratching.

Answer 289

The diagnosis is Bacillary Angiomatosis.

Answer 290

Treatment involves erythromycin or doxycycline for 3 or more months, with combination therapy for severe cases.

Answer 291

The likely diagnosis is Bacillary Angiomatosis.

Answer 292

Complications to monitor for include peliosis hepatis, splenic peliosis, and culture-negative endocarditis.

Answer 293

The likely diagnosis is Trench Fever.

Answer 294

Treatment includes 28 days of oral doxycycline plus 14 days of IV gentamicin, or a 4-6 week course of oral doxycycline, erythromycin, or azithromycin for uncomplicated cases.

Answer 295

The management for uncomplicated Bacillary Angiomatosis includes: 1. Erythromycin or doxycycline for 3 or more months. 2. Alternatives include Azithromycin and clarithromycin. 3. Severe cases may require combination therapy with erythromycin or doxycycline plus a rifamycin, and intravenous therapy may be needed initially.

Answer 296

The typical cutaneous findings include: - Characteristic lesion: reddish-purple, angiomatous papule approximately 1 cm in diameter. - Lesion may be nodular or pedunculated. - Surface is smooth or verrucous and may ulcerate and occasionally bleed. - Less common variants include subcutaneous nodules and hyperkeratotic plaques.

Answer 297

The laboratory tests include: 1. Skin biopsy for histology, Warthin-Starry staining, and PCR. 2. IFA (Immunofluorescence Assay) may also be used.

Answer 298

Non-cutaneous findings may include: - Peliosis hepatis: Symptoms include abdominal pain, hepatomegaly, splenomegaly. - Splenic peliosis: Symptoms include thrombocytopenia and pancytopenia.

Answer 299

Imaging findings include: - Abdominal CT shows organomegaly and scattered hypodense lesions. - Radiographs may reveal lytic lesions with cortical destruction and periosteal reaction.

Answer 300

Oroya fever is characterized by: - Acute bacteremic syndrome - Hemolytic anemia - Associated increase in opportunistic infections.

Answer 301

The causative agent is Bartonella bacilliformis. The only known reservoirs are humans.

Answer 302

First-line treatment options include: 1. Ciprofloxacin 2. Combination therapy with chloramphenicol and a -lactam for 14 days.

Answer 303

During the hemolytic phase, patients are predisposed to infections by opportunistic pathogens such as Salmonella spp., Shigella dysenteriae, and others.

Answer 304

The incubation period is typically 60 days, with a range of 1 to 30 weeks.

Answer 305

Carrion Disease includes Oroya fever and verruga peruana. Management involves ciprofloxacin or chloramphenicol with a β-lactam for Oroya fever, and rifampicin or alternatives for verruga peruana.

Answer 306

The two main diseases are Oroya fever and verruga peruana.

Answer 307

Lesions may erupt over a course of 3 to 6 months, but they may continue to appear for years if left untreated.

Answer 308

Inspecting Giemsa-stained blood smear for blue-colored intraerythrocytic or extraerythrocytic bacilli.

Answer 309

To visualize Bartonella, which may be found as intracellular inclusions and free organisms in the extracellular matrix.

Answer 310

Carrion disease includes Oroya fever and verruga peruana, typically found in the Andean valleys of Peru, Colombia, and Ecuador. The causative agent is B. bacilliformis, and the vector is the sand fly (L. verrucarum).

Answer 311

Oroya fever is associated with: - Acute bacteremic syndrome - Hemolytic anemia - Increased risk of opportunistic infections. Verruga peruana appears 2 months to several years after Oroya fever, characterized by eruptive crops of angiomatous nodular lesions.

Answer 312

Non-cutaneous findings include: - Prodrome: fever, chills, malaise, headache, anorexia, myalgias, arthralgias. - Rapid deterioration with pallor, jaundice, dyspnea, confusion, and severe hemolytic anemia.

Answer 313

Diagnosis involves: - Giemsa-stained blood smear to identify B. bacilliformis. - Blood cultures showing positive results within 2 to 4 weeks during the acute phase.

Answer 314

Management includes: - First-line treatment for uncomplicated Oroya fever: ciprofloxacin or combination therapy with chloramphenicol and a-lactam for 14 days. - For severe disease: ciprofloxacin plus ceftriaxone.

Answer 315

The diagnosis is Carrion Disease, including Oroya fever and verruga peruana.

Answer 316

Complications to monitor for include opportunistic infections like Salmonella, Shigella, and disseminated histoplasmosis during the hemolytic phase of Oroya fever.

Answer 317

Diagnostic tests include Giemsa-stained blood smear, blood cultures during the acute phase, and skin biopsy with Warthin-Starry or Giemsa stains.

Answer 318

The diagnosis is Oroya fever, a phase of Carrion Disease.

Answer 319

Carrion disease includes Oroya fever and verruga peruana, typically found in the Andean valleys of Peru, Colombia, and Ecuador. The causative agent is Bartonella bacilliformis, and the vector is the sand fly (Lutzomyia verrucarum).

Answer 320

Oroya fever presents with acute bacteremic syndrome, hemolytic anemia, and increased risk of opportunistic infections.

Answer 321

Diagnosis involves Giemsa-stained blood smear, blood cultures collected during the acute phase, and skin biopsy using Warthin-Starry or Giemsa stains.

Answer 322

First-line treatment includes ciprofloxacin or combination therapy with chloramphenicol and a-lactam for 14 days.

Answer 323

When treated with antibiotics, the mortality rate is less than 10%.

Answer 324

The classic cutaneous manifestation is rose spots, which occur in approximately 30% of cases.

Answer 325

Common findings include fever, malaise, anorexia, nausea, myalgias, headache, and abdominal pain.

Answer 326

Enzymes frequently exceed the upper limit of normal by 2-3 times.

Answer 327

Complications of enteric fever can arise in **10% to 15%** of patients and include:

Answer 328

**GI bleeding**: occurs most frequently.

Answer 329

**Intestinal perforation**: the most serious complication, occurring in **1% to 3%** of hospitalized patients, usually affecting the ileum.

Answer 330

**Chronic carrier state**: occurs in **1% to 4%** of cases.

Answer 331

**Encephalopathy**: can also occur in some patients.

Answer 332

Diagnosis of enteric fever is primarily through laboratory testing, which includes:

Answer 333

**Blood cultures**: standard mode of diagnosis, positive in **40% to 80%** of cases.

Answer 334

**Bone marrow culture**: more sensitive, positive in **80% to 95%** of cases even after several days of antibiotics; however, it is invasive and reserved for complicated cases.

Answer 335

The epidemiology of enteric fever caused by Salmonella includes:

Answer 336

Approximately **13.5 million cases** worldwide each year, with the greatest prevalence among children and young adults.

Answer 337

Endemic in many developing countries, especially in resource-poor areas with overcrowding and inadequate sanitation.

Answer 338

Regions with the greatest density of disease include **southcentral and southeastern Asia** and areas of **southern Africa**.

Answer 339

Humans are the only hosts of **S. typhi**, which is the most frequent cause of enteric fever, while **S. paratyphi A** is responsible for a growing portion of disease in multiple Asian countries.

Answer 340

Enteric Fever is diagnosed using blood cultures (positive in 40-80% of cases) or bone marrow cultures (positive in 80-95% of cases, even after antibiotics). Serologic tests may identify chronic carriers.

Answer 341

Complications include GI bleeding, intestinal perforation, encephalopathy, and chronic carrier state. Management involves antibiotics like ciprofloxacin, azithromycin, or ceftriaxone, with surgical intervention for perforation.

Answer 342

Enteric fever and gastroenteritis.

Answer 343

Salmonella enterica subsp. enterica serovar Typhi (Salmonella typhi).

Answer 344

Approximately 13.5 million cases.

Answer 345

Classic cutaneous manifestation presenting several days after the onset of symptoms, occurring in approximately 30% of cases.

Answer 346

Intestinal perforation, occurring in 1% to 3% of hospitalized patients.

Answer 347

By ingesting contaminated water or food, usually while traveling or residing in developing countries.

Answer 348

Blood cultures.

Answer 349

Positive in 80% to 95% of cases even after several days of antibiotics.

Answer 350

Fever, malaise, anorexia, nausea, myalgias, and abdominal pain.

Answer 351

Bacteria infiltrate tissue macrophages of the liver, spleen, and bone marrow, which may serve as sources for infection relapse.

Answer 352

The classic cutaneous manifestation of enteric fever is **rose spots**, which present several days following the onset of symptoms. They occur in approximately **30% of cases** and are more likely to be observed in patients where antibiotic treatment has been delayed. Characteristics include: - Asymptomatic, blanching, erythematous to pale-pink papules - Usually found on the abdomen, chest, or back - Occur in crops that fade over **3 to 5 days**.

Answer 353

Common non-cutaneous findings associated with enteric fever include: 1. **Fever**: Initially low, rising in a stepwise fashion, often reaching **39°C to 40°C (102.2°F to 104°F)** with relative bradycardia. 2. **Malaise, anorexia, nausea, myalgias, headache**. 3. **Abdominal pain** and either diarrhea or constipation (diarrhea is common in children and HIV patients, while constipation is more likely in adults). 4. **Physical exam findings**: Abdominal tenderness, hepatosplenomegaly. 5. **Neurological symptoms**: Intermittent confusion or apathy, and convulsions in young children. 6. **Hematological changes**: Reduced white cell counts, hemoglobin, and platelets; liver enzymes frequently 2-3 times the upper limit.

Answer 354

Complications of enteric fever can arise in **10% to 15%** of patients and include: - **GI bleeding**: Occurs most frequently. - **Intestinal perforation**: The most serious complication, occurring in **1% to 3%** of hospitalized patients, usually affecting the ileum. It may present overtly as an acute abdomen or subtly with worsening abdominal pain, rising heart rate, and falling blood pressure. - **Chronic carrier state**: Occurs in **1% to 4%** of cases, which can lead to ongoing transmission of the disease. - **Encephalopathy**: A rare but serious complication that can affect neurological function.

Answer 355

Salmonella enterica causes enteric fever primarily through ingestion of contaminated water or food, especially while traveling or residing in developing countries. The pathways for its entry into the body include: 1. **Entry via M cells**: These are antigen-presenting cells associated with lymphoid tissue throughout the gut. 2. **Uptake by epithelial cells**: This is mediated by the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which is mutated in cystic fibrosis.

Answer 356

The primary laboratory tests for diagnosing enteric fever include: - **Blood cultures**: This is the most effective method for confirming the diagnosis.

Answer 357

Blood cultures are the standard mode of diagnosis for enteric fever, with a positive result in **40% to 80%** of cases.

Answer 358

Bone marrow cultures are more sensitive, with a positive result in **80% to 95%** of cases even after several days of antibiotics. However, it is invasive and reserved for complicated cases.

Answer 359

The likely diagnosis is Enteric Fever caused by Salmonella. ## Footnote First-line treatment includes antibiotics like ciprofloxacin, azithromycin, or ceftriaxone.

Answer 360

Complications include GI bleeding, intestinal perforation, encephalopathy, and chronic carrier state.

Answer 361

Laboratory tests include blood cultures (positive in 40-80% of cases) and bone marrow cultures (positive in 80-95% of cases, even after antibiotics).

Answer 362

Treatment involves azithromycin or ceftriaxone, as ciprofloxacin is no longer recommended as first-line empirical treatment due to rising resistance in South Asia.

Answer 363

Imaging may reveal hepatosplenomegaly and scattered hypodense lesions in the liver or spleen on abdominal CT.

Answer 364

The pathogenesis involves Salmonella breaching the intestinal epithelium, replicating in the submucosa, and disseminating via the blood and lymphatic system, leading to systemic infection.

Answer 365

Laboratory tests include blood cultures (positive in 40-80% of cases) and bone marrow cultures (positive in 80-95% of cases, even after antibiotics).

Answer 366

Treatment involves azithromycin or ceftriaxone, as ciprofloxacin is no longer recommended as first-line empiric treatment due to rising resistance in South Asia.

Answer 367

The classic cutaneous manifestation of enteric fever is **rose spots**, which present several days following the onset of symptoms.

Answer 368

Approximately **30% of cases** experience symptoms following the onset.

Answer 369

Symptoms are more likely to be observed in patients where antibiotic treatment has been delayed.

Answer 370

Characteristics include: - Asymptomatic, blanching, erythematous to pale-pink papules - Usually found on the abdomen, chest, or back - Occur in crops that fade over **3 to 5 days**.

Answer 371

Common non-cutaneous findings include: 1. **Fever**: Initially low, rising in a stepwise fashion, often reaching **39°C to 40°C (102.2°F to 104°F)** with relative bradycardia. 2. **Gastrointestinal symptoms**: Abdominal pain, diarrhea (common in children and HIV patients), or constipation (more likely in adults). 3. **Physical exam findings**: Abdominal tenderness, hepatosplenomegaly. 4. **Neurological symptoms**: Intermittent confusion or apathy, and convulsions in young children. 5. **Hematological changes**: Reduced white cell counts, hemoglobin, and platelets; liver enzymes frequently **2-3 times** the upper limit of normal.

Answer 372

Complications arise in **10% to 15%** of patients and include: - **GI bleeding**: Occurs most frequently. - **Intestinal perforation**: The most serious complication, occurring in **1% to 3%** of hospitalized patients, usually affecting the ileum. - **Chronic carrier state**: Occurs in **1% to 4%** of cases. - **Encephalopathy**: A rare but serious complication.

Answer 373

Salmonella enterica causes enteric fever through ingestion, typically via contaminated food or water.

Answer 374

Salmonella enterica causes enteric fever primarily through ingestion of contaminated water or food, especially while traveling or residing in developing countries.

Answer 375

The pathways for its entry into the body include: 1. **Entry via M cells**: Antigen-presenting cells associated with lymphoid tissue throughout the gut. 2. **Uptake by epithelial cells**: Mediated by the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which is mutated in cystic fibrosis.

Answer 376

Once inside, bacteria replicate in the submucosa and can cause hypertrophy of Peyer's patches, leading to systemic infection.

Answer 377

Laboratory tests for diagnosing enteric fever include: - **Blood cultures**: Standard mode of diagnosis, positive in **40% to 80%** of cases. - **Bone marrow culture**: More sensitive, positive in **80% to 95%** of cases even after several days of antibiotics; however, it is invasive and reserved for complicated cases.

Answer 378

Rhinoscleroma progresses through three phases: 1. Atrophic (nasal blockage and foul-smelling discharge) 2. Proliferative (granulomatous nodules and nasal deformity) 3. Cicatricial (extensive sclerosis).

Answer 379

Diagnosis involves isolating K. rhinoscleromatis from cultures, identifying Mikulicz cells in biopsied tissue, and using Warthin-Starry silver stain or CD68 immunostaining to visualize the bacteria.

Answer 380

A patient with a history of nasal blockage and foul-smelling discharge develops granulomatous nodules and nasal deformity.

Answer 381

The diagnosis is Rhinoscleroma caused by Klebsiella rhinoscleromatis.

Answer 382

Histological findings include Mikulicz cells (vacuolated histiocytes containing bacteria) and Russell bodies, visualized with Warthin-Starry silver stain or PAS staining.

Answer 383

A patient presents with nasal obstruction and purulent discharge.

Answer 384

Treatment involves prolonged antibiotic therapy with tetracycline, rifampicin, or ciprofloxacin, combined with surgical correction of airway obstructions.

Answer 385

Imaging may show nonenhancing homogeneous soft-tissue masses with nodular deformity.

Answer 386

Confirmation involves identifying Mikulicz cells in biopsied tissue and isolating K. rhinoscleromatis from cultures.

Answer 387

The three phases of Rhinoscleroma are: atrophic (nasal blockage and foul-smelling discharge), proliferative (granulomatous nodules and nasal deformity), and cicatricial (extensive sclerosis).

Answer 388

Confirmation involves identifying Mikulicz cells in biopsied tissue and isolating K. rhinoscleromatis from cultures.

Answer 389

Haemophilus influenzae is a **fastidious, Gram-negative coccobacillus** that grows on **chocolate agar** and requires **hemin (factor X)** and **nicotinamide adenine dinucleotide (factor V)** for growth.

Answer 390

Typical Hib facial cellulitis in children includes: 1. Age: **3 to 24 months** 2. Usually follows a **mild upper respiratory tract infection** 3. Symptoms: **high fever**, irritability, and **unilateral facial swelling** 4. Affected area: **warm, edematous, and erythematous**, often with a **violaceous hue**.

Answer 391

Hib cellulitis is frequently associated with **bacteremia**, with **positive blood cultures** found in approximately **75% of patients**. This indicates a systemic infection that may require more aggressive management.

Answer 392

To confirm Hib cellulitis, the following diagnostic methods are used: 1. **Culture of the affected area** to identify the organism. 2. Ruling out other common organisms, including **streptococci and staphylococci**.

Answer 393

The management of Hib cellulitis typically involves the use of **third-generation cephalosporins**, such as **ceftriaxone** or **cefotaxime**, which are considered the drugs of choice.

Answer 394

Hib cellulitis presents with high fever, irritability, and unilateral facial swelling with a violaceous hue, often following an upper respiratory infection. Management involves third-generation cephalosporins like ceftriaxone or cefotaxime.

Answer 395

It is a fastidious, Gram-negative coccobacillus.

Answer 396

Meningitis, epiglottitis, and cellulitis, especially facial cellulitis in children.

Answer 397

Children between 3 and 24 months of age.

Answer 398

High fever, irritability, and unilateral facial swelling, especially in the buccal or periorbital region.

Answer 399

Warm, edematous, and erythematous, classically with a violaceous hue.

Answer 400

They are found in 75% of patients, indicating frequent association with bacteremia.

Answer 401

Third-generation cephalosporins, such as ceftriaxone or cefotaxime, are the drugs of choice.

Answer 402

Lumbar puncture has been discontinued as a practice for diagnosis.

Answer 403

Lumbars puncture. ## Footnote Lumbars puncture has been discontinued as a practice for diagnosis.

Answer 404

Culture of the affected area to rule out streptococci and staphylococci.

Answer 405

Typical Hib facial cellulitis presents in children between 3 and 24 months of age, usually following a mild upper respiratory tract infection. Patients rapidly develop: 1. **High fever** 2. **Irritability** 3. **Unilateral facial swelling**, especially in the buccal or periorbital region 4. The affected area is **warm, edematous, and erythematous**, classically with a **violaceous hue**.

Answer 406

To confirm Hib cellulitis, the following diagnostic methods are used: 1. **Culture of the affected area** - to rule out other common organisms, including streptococci and staphylococci. 2. **Blood cultures** - positive in approximately 75% of patients with Hib cellulitis.

Answer 407

The management protocol for Hib cellulitis includes the use of **third-generation cephalosporins**. The drugs of choice are: - **Ceftriaxone** - **Cefotaxime**.

Answer 408

The likely diagnosis is cellulitis caused by Haemophilus influenzae.

Answer 409

The likely diagnosis is cellulitis caused by Haemophilus influenzae.

Answer 410

Management involves third-generation cephalosporins like ceftriaxone or cefotaxime.

Answer 411

Additional tests include culture of the affected area to rule out other organisms like streptococci and staphylococci.

Answer 412

The pathogenesis involves Haemophilus influenzae entering the bloodstream, leading to bacteremia and cellulitis, often with a violaceous hue.

Answer 413

Typical clinical features of Hib facial cellulitis include: - **Age group**: Children between 3 and 24 months - **Preceding condition**: Usually follows a mild upper respiratory tract infection - **Symptoms**: - Rapid onset of **high fever** - **Irritability** - **Unilateral facial swelling**, particularly in the buccal or periorbital region - **Affected area**: Warm, edematous, and erythematous, often with a **violaceous hue**

Answer 414

To confirm Hib cellulitis and rule out other organisms, the following diagnostic methods are used: 1. **Culture of the affected area**: This helps identify the presence of Hib and rule out other common organisms such as streptococci and staphylococci. 2. **Blood cultures**: Positive blood cultures are found in approximately 75% of patients with Hib cellulitis. ## Footnote Lumbar puncture has been discontinued as a practice for diagnosis in this context.

Answer 415

The recommended management for Hib cellulitis includes: - **Antibiotic therapy**: Third-generation cephalosporins are the drugs of choice, specifically: - **Ceftriaxone** - **Cefotaxime** These antibiotics are effective in treating the infection caused by Haemophilus influenzae.

Answer 416

1. Cat Scratch Disease (CSD) - Species: Bartonella henselae - Vector: Cat flea (Ctenocephalides felis) 2. Trench Fever - Species: Bartonella quintana - Vector: Human body louse (Pediculus humanus) 3. Bacillary Angiomatosis - Species: Bartonella henselae - Vector: Cat flea (Ctenocephalides felis) 4. Carrion's Disease - Species: Bartonella bacilliformis - Vector: Sand fly (Lutzomyia verrucarum)

Answer 417

1. **Serology**: Indirect fluorescent antibody assay. 2. **PCR**: Polymerase chain reaction to identify species. 3. **Blood culture**: May identify organism, but cultures usually negative.

Answer 418

- **Mild to moderate cases**: No treatment recommended. - **Severe cases**: Consideration of: 1. **Azithromycin**: 5 days. 2. **Doxycycline**: 14 days. 3. **Rifampin**: 14 days or streptomycin.

Answer 419

- Symptoms develop after 40 days of incubation: - Initial symptoms: Fever, headache, malaise, myalgias. - Later symptoms: Severe hemolytic anemia with jaundice, splenomegaly, and generalized lymphadenopathy. - Lesions resembling bacillary angiomatosis may develop 2 months later.

Answer 420

Lutzomyia verrucarum (sand fly).

Answer 421

It is a type of sand fly.

Answer 422

Fever, chills, malaise, headache, weight loss, and regional swelling of lymph nodes.

Answer 423

Serology using indirect fluorescent antibody assay or PCR.

Answer 424

Doxycycline or erythromycin for 7 days.

Answer 425

Severe hemolytic anemia with jaundice and generalized lymphadenopathy.

Answer 426

Approximately 40 days.

Answer 427

Fever of 5 to 20 days' duration accompanied by severe headache and myalgias.

Answer 428

It can be life-threatening.

Answer 429

**Clinical Features:** - Erythema nodosum or papules at inoculation site - Fever, chills, malaise, headache, weight loss, and regional lymphadenopathy **Laboratory Tests:** - Serology (indirect fluorescent antibody assay) - PCR may identify organism - Cultures usually negative.

Answer 430

**Treatment Options:** - Doxycycline or erythromycin for 14 days **Course of Disease:** - Symptoms may resolve in 1 to 3 weeks, but relapses can occur. Severe cases may require hospitalization.

Answer 431

Common laboratory tests include serology and PCR.

Answer 432

1. Blood smear with Giemsa stain to reveal the presence of bacilli. 2. Biopsy of skin lesions for diagnostic confirmation.

Answer 433

These tests help confirm the diagnosis of Bacillary Angiomatosis, which is crucial for appropriate management.

Answer 434

After 10-40 days of incubation, symptoms include fever, chills, malaise, headache, and myalgias. Severe hemolytic anemia with jaundice and generalized lymphadenopathy may develop.

Answer 435

Supportive care and antibiotics (e.g., doxycycline or streptomycin) for 14 to 21 days.

Answer 436

1. Erythema nodosum or inoculation site papules. 2. Fever, chills, malaise, headache, weight loss, and regional lymphadenopathy.

Answer 437

1. Serology: Indirect fluorescent antibody assay. 2. PCR may identify organism. 3. Cultures usually negative.

Answer 438

Course of antibiotics (e.g., doxycycline or erythromycin).

Answer 439

Generally self-limiting, but may require supportive care for severe cases. Lymphadenopathy may persist for several weeks.

Answer 440

After 10-40 days of incubation, symptoms include fever, chills.

Answer 441

Symptoms include fever, chills, malaise, headache, and myalgias.

Answer 442

Severe hemolytic anemia with jaundice and generalized lymphadenopathy.

Answer 443

Blood smear may show bacilli.

Answer 444

Supportive care.

Answer 445

Doxycycline or streptomycin for 14 to 21 days.

Answer 446

Vectors and reservoirs include: | Species | Vector | Reservoir | |-------------------------------------|------------------------------------------|-----------| | Bartonella bacilliformis | Lutzomyia verrucarum (sand fly) | Human | | Bartonella henselae | Ctenocephalides felis (cat flea) | Cat | | Bartonella quintana | Pediculus humanus (human louse) | Human |

Answer 447

Each vector is responsible for transmitting specific Bartonella species, leading to distinct diseases in their respective reservoirs.