Fever and Rash Flashcards
Papules
Small, solid, palpable lesions elevated above the plane of the skin
Nodules
Masses located deeper within or below the skin
Vesicles and bullae
Blisters of differing size
Pustules
Small, palpable lesions filled with pus
Macule
Flat,nonpalpable, blanching
Purpura or petechiae
Nonblanching due to extravasation of blood
Erythema
Hyperpigmented
Blanching erythematous lesions due to vasodilatation
MACULOPAPULAR RASH Viral illness causes
Measles (Rubeola)
Rubella (German measles)
Erythema infectiosum (Parvovirus)
Roseola (exanthema subitum, usually HHV-6)
Coxsackie
Measles (Rubeola) characteristics
Paramyxoviridae – enveloped (-)ssRNA viruses
Cough, Coryza, Conjunctivitis, posterior Cervical adenopathy, Koplik’s spots precede rash
Rash
Nonpruritic
Cephalocaudal spread
Face -> spreads downward
Cetrifugalspread
Face/neck/trunk -> extremities
Rubella
Togaviridae- enveloped
(+)ssRNA
“little red” – mild measles
Rash also starts on face
Petechial lesions on soft palate, NO Koplik’s spots
Fever,lymphadenopathy
Parvovirus B19
Parvoviridae,unenvelopedssDNA
Erythema infectiosum,“5th disease”- school age children
Clinical manifestations
Viral syndrome=Fever,malaise,GI upset, lymphadenopathy
Rash= “slapped cheek” with relative perioral pallor
Some have secondary diffuse lacy reticular rash
Parvo B19 associations
Infects erythroid precursors
Reticulocytopenia: Severe – pure red cell aplasia
HIV patients, Hemoglobinopathies (SCD, thalassemia)
Acute polyarthritis in adults
Congenital infectionHydrops fetalis
Roseola
HHV-6 and HHV-7
Childhood illness
High fever prior to rash
Rash starts on face or trunk
Syphilis primary sx
Spirochete,Treponemapallidum
Varied skin manifestations
Primary
Chancre
Site of inoculation
Oropharynx
Genitals
Painless
Self-resolving
Syphilis
Varied skin manifestations
Secondary
Disseminating phase
Flu-like symptoms, Lymphadenopathy
Maculopapular rash - Nonpruritic, Palm/soles involved
Condyloma lata, Copper penny spots
Pustules, Mucous patches
Alopecia
Erythema migrans
Lyme disease
Bite from Ixodes tick
Borrelia burgdorferi
Pathognomonic “target” or “bull’s eye” early disease
Fungal causes of nodules
Cryptococcus
Histoplasma
Coccidioides
Sporotrichosis
Nocardia characteristics
Direct inoculation of organisms into the skin
During gardening or farming;
Puncture by a thorn or splinter
Manifestations
Ulcerations, cellulitis, nodules, and subcutaneous abscesses
May involve regional lymphatics, producing a nodular lymphangitis
“sporotrichoid nocardiosis”
Nocardia Diagnosis
Modified AFB stain
Less mycolic acid in cell wall than
mycobacterial species (AFB+)
Nocardia easily decolorizes, will not be visible on normal AFB stain
Culture
Variable colony morphology
Sporotrichosis characteristics
Sporothrix schenkii
Inoculated by organic matter Rose bush
Gardeners
Erythematous nodules
Ulceration
Follow lymphatics
“sporotrichoid spread”
Cryptococcus characteristics (can cause nodules
Large capsule
india ink stain
CNS, lung, skin
Immunosuppressed, HIV
Bird droppings, soil
Molluscum contagiosum can cause nodules (characteristics )
poxvirus
spread by contact
common in childhood
seen in immunosuppression, HIV
Noninfectious nodules
Erythema nodosum
Systemic lupus erythematosis
Sarcoidosis
Ulcerative colitis
Crohn’s disease
Medications
Neoplasm
Vesicles (<0.5cm)
Elevated; Fluid-filled
Herpes viruses – dsDNA viruses
Erythematous base
Tzank smear, multinucleated giant cells
Varicella zoster
Chickenpox
Dermatomal reactivation (shingles)
HSV vesicle characteristics
dsDNA
Clustered lesion
Type 1 perioral
Type 2 genital
CoxsackieTypeA
Herpangina –
painful palatal ulcers (HFM disease)
Coxsackie Type B
Cardiac manifestations
Myocarditis, cardiomyopathy, arrhythmias
Pleurodynia
Bullous lesions size
(>0.5 cm)
Staphylococcal scalded skin syndrome (SSSS)
Systemic spread of Staphylococcus aureus exfoliative toxins (ETs)
Primary infection localized elsewhere
Cause intraepidermal splitting through the granular layer by cleavage a desmosomal protein that mediates cell-cell adhesion granular layer.
Vibrio vulnificus
Following water exposure or ingestion of contaminated seafood (shellfish)
Severe disease with liver disease
Vesiculopustular
Some lesions with clear fluid (vesicular) some with purulent material (pustular)
FOLLICULITIS seen in
Pseudomonas:Hottubexposure
Staphylococcalfolliculitis
Erythema characteristics
Diffuseredness,blanching,vasodilatation
Cellulitis
Gram positive
Staph,strep
Risks – any breach in skin integrity.
Tinea,venousstasis,onychomycosis
Treatment – antibiotics, treat underlying cause
Erysipelas (erythema) characteristics
Group A strep
Well-demarcated,painful
Lymphangitis characteristics
Gram positive – Group A strep, staph
Follows lymphatics
“streaking”,associated lymphadenopathy
Risks – lymph node resection
Petechiae (<3 mm) & Purpura (> 3mm)
Characteristics
Extravasated blood, thrombosed vessels
will NOT blanch with pressure
Purplish in color
Neisseria meningitides characteristics
Gram negative diplococci
Capsule inhibits phagocytosis
IgA protease allows colonization of respiratory tract
Lipopolysaccharide endotoxin (LPS)
Most common cause of bacterial meningitis in children & young adults; Rapidly fatal if untreated
Meningococcemia- Petechial rash; Skin, mucous membranes; Conjunctivae
Risks:Terminal complement deficiency (C5-C8)
Rickettsia rickettsii (Rocky Mountain Spotted Fever)
Small intracellular gram negative coccobacilli
Tick vector (Dermacentor)
Rash starts on palms & soles, spreads to trunk and face
“spotless RMSF”
Monomicrobial (“Flesh-eating bacteria”) necrotizing fascitis
Group A beta-hemolytic streptococci (GAS)
Pyrogenic exotoxins act as superantigens and trigger massive cytokine release, causing sepsis and shock
GAS is susceptible to bacitracin
Also S. aureus
Polymicrobial necrotizing fascitis
Gram positive: streptococci
Gram negative: Enterobacteriaceae
E. coli, Enterobacter, Klebsiella, Proteus
At least ONE anaerobe: Bacteroides or Peptostreptococcus
Clostridial myonecrosis cultures
Double zone of hemolysis with an inner zone of β hemolysis surrounded by an outer zone of partial hemolysis
Reverse CAMP test on plate with Group B strep (S. agalactiae)
