Dermatology Flashcards
What are the ABCDEs of melanoma?
- asymmetry
- border irregularities
- color irregularities
- diameter greater than 6mm
- evolution over time
Describe the diagnosis and treatment of melanoma?
- only a full thickness biopsy is sufficient
- treat with excision including large margins
Where does melanoma commonly metastasize to?
the brain
What are risk factors for squamous cell carcinoma?
- sun exposure
- transplant/chronic immunosuppression
- chronic irritation (e.g. scar, wound, etc.)
How is basal cell carcinoma biopsied?
a shave biopsy is acceptable and full thickness biopsy isn’t required
What is the benefit of Mohs surgery?
it permits removal of basal cell carcinoma with the loss of only the smallest amount of normal tissue
Describe the etiology, presentation, and treatment of Kaposi sarcoma.
- due to HHV-8
- presents as reddish/purplish lesions on the skin but are also found in the GI tract and lung of those with a CD4 count less than 100
- treat with HAART therapy and the lesions will resolve as the CD4 count rises; otherwise, vincristine or interferon injections are helpful
Describe the presentation, malignant potential, and treatment of actinic keratoses.
- present as rough, scaly lesions that appear as if they may ulcerate
- they are premalignant with a small risk for transformation into squamous cell carcinoma, so must be treated
- use curettage, cryotherapy, laser ablation, topical 5-FU, or imiquimod
What is imiquimod?
a local immunostimulant used to treat actinic keratoses, molluscum contagious, and condyloma acuminata
Describe the presentation, malignant potential, and treatment of seborrheic keratoses.
- these are hyperpigemented lesions with a stuck on appearance
- they carry no malignant potential so removal is only for cosmetic reasons
Describe the pathophysiology, presentation, and treatment of eczema.
- also known as atopic dermatitis, it is associated with overactivity of mast cells and the immune system
- presents as an itch that rashes in those with a history of atopy; lesions are scaly, rough areas of thickened skin
- treat with skin moisturizers and avoidance of skin trauma or irritation which promote the itch-scratch cycle
- use steroids, tacrolimus and pimecroliumus, antihistamines, and phototherapy for medical management
What is Tacrolimus?
a T cell inhibiting agent
Describe the presentation and treatment of psoriasis.
- presents as non-pruritic, silvery, scaly plaques
- treat local disease with steroids, vitamin A and vitamin D ointment, coal tar preparation, and tacrolimus or pimecroliumus
- treat extensive disease with phototherapy, TNFa inhibitors, and methotrexate (last resort due to toxicity)
What skin condition is described as diffuse erythematous macular lesions that spare the palms and soles and is preceded by a herald patch? How is it treated?
- this is pityriasis rosea
- it is self-limited but can be treated with steroids or phototherapy
Describe the pathophysiology and treatment of seborrheic dermatitis.
- it is a hypersensitivity reaction to dermal infection with noninvasive dermatophytes
- treat with steroids and antifungals
With which medications is drug-induced pemphigus vulgaris associated?
primarily ACE inhibitors as well as pencillamine, penicillin, and phenobarbital
Compare and contrast pemphigus vulgaris and bullous pemphigoid.
- vulgaris involves bullae that easily rupture and involve the mouth and is characterized by a positive Nikolsky sign
- bullous pemphigoid is much milder with intact bullae, no mucosal involvement, and a negative Nikolsky sign
- furthermore, bullous pemphigoid has a linear deposition of IgG whereas vulgaris has a net-like distribution
How are pemphigus vulgaris and bullous pemphigoid diagnosed and treated?
- for both, biopsy and immunofluorescence is the most accurate test
- vulgaris is treated with steroids, azathioprine, mycophenolate, and sometimes IVIG or rituximab
- bullous pemphigoid responds to these but more mild cases can be treated with dapsone or nicotinamide
Describe the pathophysiology, presentation, diagnosis, and treatment of porphyria cutanea tarda.
- caused by a uroporphyrin decarboxylase deficiency
- presents with blistering of sun-exposed areas, particularly the back of the hands, in those with hepatitis C, estrogen use, and iron overload
- the most accurate test is an elevated 24-hour urine uroporphyrin level
- treat the underlying condition, namely hepatitis C
How is impetigo treated?
- mild disease is treated with topical mupirocin while more severe disease is treated with oral dicloxacillin or cephalexin
- if MRSA is suspected, use doxy, clinda, or bactrim
Describe the pathophysiology, presentation, and treatment of erysipelas.
- due to an infection, usually Strep, of the deeper skin levels with invasion of the dermal lymphatics
- for this reason it produces a well-demarcated erythematous region of skin as well as systemic signs
- treat mild disease with oral methicillin or MRSA antibiotics; IV antibiotics are required for systemic illness including fever
What is the difference between treating impetigo and cellulitis?
cellulitis is a deeper infection, thus topical antibiotics are insufficient
What is unique about treating erysipelas versus other skin infections?
it has the potential to invade dermal lymphatics, so if systemic symptoms are present like fever, IV antibiotics are required
What is the difference between folliculitis, furuncles, and carbuncles?
- folliculitis is a minor infection around a hair follicle
- furuncles are abscesses around a hair follicle
- carbuncles are collections of furuncles
Describe the presentation, diagnosis, and treatment of tinea.
- presents as a pruritic, erythematous annular border with central scaling
- the best initial test is KOH prep and the most accurate is fungal culture
- the best initial therapy is a topical anti fungal; if hair or nails are involved use oral terbinafine
What is the preferred treatment of oral and vaginal candidiasis?
both should be treated with topical antifungals such as clotrimazole or nystatin
Describe the presentation and treatment of staphylococcal scalded skin and toxic shock syndromes.
- they both present with a rash similar to TEN including mucous membrane involvement and a positive Nikolsky sign
- toxic shock has additional multi organ involvement including hypotension, renal dysfunction, CNS involvement, and liver dysfunction
- treat with supportive care and antistaphylococcals
Describe the progressive treatment of acne.
- begin with topical antibacterials like benzoyl peroxide
- add topical antibiotics clindamycin or erythromycin
- add topical vitamin A derivatives
- add oral antibiotics minocycline or doxycycline
- add oral vitamin A in the form of isotretinoin
