Dermatology #2 Flashcards
What are the four main pathophysiology units of acne vulgaris?
1) follicular hyperkeratiniziation
2) increased sebum production
3) overgrowth of Propionibacterium
4) inflammatory response
Clinical manifestations of acne vulgaris depending on the type
- Comedones: open (blackheads) and closed (whiteheads)
- Inflammatory: papules or pustules surrounded by inflammation
- Nodular or Cystic: often heals with scarring
Treatment for mild acne vulgaris
-Topical: Azelaic Acid, Salicylic acid, Benzoyl Peroxide, or Tretinoin or topical ABX (Clinda, Erythromycin)
Treatment for moderate acne vulgaris
-Tx for mild + Oral ABX (Minocycline or Doxy), Spironolactone
Treatment for severe acne vulgaris
-Oral Isotretinoin
Adverse effects of isotretinoin
- Dry skin and lips (MC)
- Highly teratogenic
- Increased triglycerides and cholesterol
- Worsening of DM
- Photosensitivity
What is a furuncle?
Deep abscess infection of the hair follicle
MCC of a furuncle
Staph A
Treatment for a furuncle
Incision and drainage
-ABX for associated cellulitis only
What is Toxicodendron dermatitis?
-Caused by poison ivy (in east), poison oak (west of Rocky Mountains), and poison sumac (southeast)
Management for dermatitis caused by poison ivy, oak, or sumac
- Cool compresses, oatmeal baths
- Avoid use of protective clothing
- wash area with detergent soap
What is Lichen Simplex Chronicus (Neurodermatitis)?
-Skin thickening in patients with atopic dermatitis secondary to repetitive rubbing and scratching (itch-scratch cycle)
Symptoms of lichen simplex chronicus?
Scaly, well-demarcated rough hyperkeratotic plaques with exaggerated skin lines
Treatment for lichen simplex chronicus
Avoid scratching the lesions
Topical corticosteroids (high-strength)
Antihistamines
Occlusive dressings
What are urticaria?
Hives
- Type I (IgE) hypersensitivity reaction
- Circumscribed hives or wheals (blanch able, raised, erythematous areas on the skin or mucous membranes) that may coalesce. Intensely pruritic
- Transient and disappear within 24 hours and new crops often occur
Initial management of choice for urticaria
Antihistamines (H1 blockers)
- H2 blockers (Ranitidine) often added if no response to H1 blockers
- Glucocorticoids added if severe, recurrent, or persistent cases
What is the pathophysiology of vitiligo?
Autoimmune destruction of melanocytes leading to skin depigmentation
Treatment for vitiligo
- Localized: Topical corticosteroids such as Topical Calcineurin inhibitors (Astragraf)
- Disseminated: Systemic phototherapy plus corticosteroids
Symptoms of cyanide poisoning
- Rapidly developing coma
- Apnea
- Cardiac derangement
Treatment for cyanide poisoning
- Hydroxocobalamin
- Cyanide kit (Amyl nitrate for inhalation, IV sodium nitrate, or thiosulfate)
Name three facts about high voltage electric current injuries
1) electricity favors the path of least resistance (nerves, muscles and blood). They suffer the greatest damage
2) AC currents 3-5 times more damaging than direct current
3) Morbidity is often greater with low voltage because high voltage propels patient away when touching it
When should you admit a patient with an electric current voltage injury?
> 600V, even if asymptomatic
-Alkalinize the urine to protect the kidney
What is a keloid?
Excess production of Type I and III collagen during wound healing
-MC in darker skinned individuals
What is the first line management for a keloid?
Corticosteroid injections (intralesional Triamcinolone) -Laser therapy or cryotherapy
A brown recluse spider (Loxosceles reclusa) has a ____ on the anterior cephalothorax. What are some effects of the venom?
-Violin pattern
- Venom is cytotoxic and hemolytic. Local burning and erythema at site of bite followed by red halo and then hemorrhagic bulla that undergoes eschar formation.
- Fever, chills, nausea, vomiting
Treatment for brown recluse bite
- Local wound care and pain control mainstay of management
- -Clean affected area with soap
- -Apply cold packs to the site
- -Keep affected body part elevated
- -NSAIDs and Tetanus prophylaxis if needed
- -ABX only needed if cellulitis develops
A black widow (Latrodectus Hesperus) produces a neurotoxin. This spider has a _____ on the underside of its belly. Symptoms of the venom include…
-Red hourglass shape
- Local symptoms (pain at bite site)
- Onset of systemic and neurologic symptoms within 30 minutes - 2 hours
- -Muscle pain, spasms, rigidity
- -Bite site is a target lesion
Treatment for black widow bite
- Wound care and pain control
- -Soap and water to clean off bite wound
- -Muscle relaxants (Benzos) if moderate to severe
- -Antivenom if not responsive to above treatment
Hand, Foot, and Mouth disease is caused by ______ and is MC in what seasons?
Coxsackievirus A
-Summer and early fall
Describe the rash of Hand, Foot, and Mouth Disease
- Oral enanthem: erythematous macule that become painful oral vesicles surrounded by thin halo of erythema (especially on buccal mucosa and tongue)
- Exanthem: grayish-yellow macular lesions on distal extremities (palms and soles)
Herpangina, caused by ______, is characterized by
-Coxsackievirus Type A
- Sudden onset high fever, stomatitis (small yellow-white lesions on posterior pharynx) that ulcerate before healing
- Anorexia due to pain
- Pharyngitis and odynophagia
What is lymphangitis?
Inflammation of the lymphatic channels due to infectious or non-infectious causes
Clinical manifestations of lymphangitis
- Red, tender streaks extending proximally from site of cellulitis
- May involve regional lymph nodes or systemic symptoms
Management of lymphangitis if associated with cellulitis
Oral: Cephalexin, Dicloxacillin (Clindamycin or Erythromycin if PCN allergy)
IV: Cefazolin, Unasyn, Ceftriaxone + Clinda
MRSA: CDB or IV Vanco or Linezolid
What is Condyloma Acuminata?
Caused by HPV infection
-Tiny painless papules evolve into soft, fleshy cauliflower like lesions occurring in genital regions or oropharynx
How to diagnose condyloma acuminata
Acetic acid application: whitening of lesion with acetic acid
Treatment for condyloma acuminata
- Most resolve spontaneously
- Cryotherapy, trichloroacetic acid, surgical excision can lead to scarring
- Topical Podophyllotoxin or Podofilox
For prevention of condyloma acuminata, what vaccine is given and what does it cover?
Gardasil 9
-HPV 6, 11, 16, 18, 31, 33, 45, 52, 58
True or False: The HPV vaccine is safe for pregnancy and lactating moms?
False
-Contraindicated in pregnancy and lactating moms
Dosing of HPV vaccine if < 15 years old
2 doses of HPV vaccine at least 6 months apart
Dosing of HPV vaccine if > 15 years old or immunocompromised
3 doses over a minimum of 6 months. Given at day 0, 2 months, and 6 months.
What is the MC benign epidermal skin tumor?
Seborrheic keratosis
Describe a seborrheic keratosis
Velvety, warty lesion with a greasy “stuck on” appearance
What is the MC premalignant skin condition?
Actinic Keratosis
Management of actinic keratosis
- Avoid sun exposure, use sunscreen
- Liquid nitrogen cryotherapy (if localized)
- Topical 5FU and Imiquimod (if multiple)
Dermatitis Herpetiformis is associated with what condition?
Celiac disease (gluten systemic enteropathy)
What is the pathophysiology of dermatitis herpetiformis
-IgA immune complex deposition in the dermal papillae
What is the definitive diagnostic for dermatitis herpetiformis?
Direct immunofluorescence (IgA deposition within the papillary dermis)
Treatment for Dermatitis herpetiformis
- Gluten free diet
- Dapsone (first line management)
Adverse effects of Dapsone
- Peripheral Neuropathy
- Hemolysis in patients with G6PD deficiency
- Cimetidine decreases effects of Dapsone
