Dermatology - Matthys Flashcards
Annular, erythematous papules, scaling, eczematous, pruritic in antecubital fossa
What is it?
Often a history of?
Other signs on PE?
Histology
Treatment
Atopic dermatitis
Type 1 Hypersensitivity response
Atopy
Allergic shiners, DM lines, allergic salute
Spongiosis, eosinophilia
Moisture, avoidance, anti-pruritics, anti-inflamm
Erythematous, non-scaling, localized w/ sepsis, fever, no muscle involvement, tender and boggy
What is it?
Risk factors?
Initiation?
Treatment?
More mild version on face?
Cellulitis
Infection of skin and CT
Stasis dermatitis, lymphedema
Trauma –> Staph/Strep
Cephalosporin, Macrolide, or Clindamycin… + Elevation
Erysipelas
Symmetric erythematous, non-scaling, tender nodules and plaques on anterior LEs.
What is it?
Main differential?
Treatment?
Erythema nodosum
Hypersensitivity inflammation of subQ fat (panniculitis)
Sarcoidosis
Anti-inflam, rest, avoidance
Erythematous, scaling w/ silvery plaque, papulosquamous
Histo?
Other findings?
3 subtypes?
Psoriasis
Acanthosis, parakeratosis, clubbed rete ridges, no granulosum, tortuous BVs
Nail pitting, Koebner, Auspitz, Woronoff’s ring (after cleared)
Plaque, pustular, guttate
Local radicular pain, then eruption of rash 2-3 days later.
Histo?
Treatment?
Herpes zoster - Shingles
Steel gray nuclei, multinucleated giant cells, eosinophilic inclusions
Antivirals, pain control, vaccine
HLA-B13
Psoriasis
Rash in the webbing of the fingers and toes
Scabies
Branny/flaky, greasy, red-yellow scales on scalp, face, chest. Flaking in hair-baring areas.
Cause?
Common in who?
Seborrheic dermatitis
Plasmodium ovale infection
MALES, HIV
DM, warm humid areas chronically have red-brown scaly macules that combine to form erosive collarette-like scale.
How to diagnose?
Cause?
Erythrasma
Woods lamp – redness
Coryne. minutissimus infection (Gram + rod)
Middle age patient w/ Hepatitis C. Pruritic papules or plaques.
Things to look for on the rash?
What else to look for? Important why?
Treatment?
Lichen planus
Wickham striae (white lines)
Oral lesions –> can lead to SCC
Low dose topical steroids
Woman present at beginning or end of spring/summer. Pruritic rose/pink scaly patches or plaques, with one larger than the rest. Span out in peculiar pattern on thorax.
What is the pattern?
What is the large patch?
Histo?
Treatment?
Pityriasis rosea
Christmas tree pattern
Herald patch (1st one)
CD4+ cells and Langerhaan’s cells in the dermis
Light therapy
Moving infection of cornified areas (skin/hair/nails). Positive KOH test.
MUST treat which area?
Cause?
Tinea
Nails – can’t kill w/ topicals
Dermatophyte infection – Trichophyton, Microsporum, Epidermophyton
Reddish-orange scaling plaques w/ redness of palms and soles. Glove-type distribution of palms. Follicular keratitis papules. Islands of sparing.
Has features of what?
Treatment?
Pityriasis rubra pilaris
Vitamin A deficiency
Retinoids
Pruritic, scaling plaques w/ red-brown shades or hypopigmented shades.
Cause?
Mimics what?
Treatment?
CTCL (mycosis fungoides)
HTLV infection
Eczema
Topical steroids, PUVA, nitrogen mustard
Young adult w/ pruritic, scarring, erythematous papules/plaques, scaling, photosensitive rash, worse in sun. On mucosa, palms and soles.
Increased risk of what?
Diagnose w/ what?
Usually does NOT have what?
Treatment?
Discoid SLE
SCC
ANA, biopsy
Systemic symptoms
Sunscreen, topical steroids
Purpura - drug reaction?
Argyria - drug reaction?
Phototoxicity - drug reaction?
Coumadin
Silver nitrate
Doxycycline
Give antibiotics, patient gets worse. What is this?
Jarisch-Herxheimer Rxn
Most drug eruptions are what hypersensitivity type?
Classic look?
Type 4
Expansive erythematous maculopapular rash
Erythematous annular plaque, coin-like, with fissures. Worse in winter.
Nummulous dermatitis
Child under 6, crusty lesion. Asymptomatic flaccid ruptured blister, commonly on face in hot weather, crowded conditions, or immunocompromised patients.
Commonly also have what? Why?
Cause?
Caution?
Treatment?
Impetigo
Atopic dermatitis –> causes break in skin barrier –> infection
Staph aureus
Very contagious
Antibiotics
Painful erythema in kids. Fever, orange-red macules. Skin peels off. Blisters. Positive nikolsky sign.
Cause?
What causes the blisters?
Cultures?
Treatment?
Staph scalded skin syndrome
Staph aureus exotoxin ET1/2
Granulosum desmosome splitting
Negative
Antibiotics, fluids
Flaccid bulla on skin w/ erosion in oral mucosa. Positive nikolsky sign. Spreads when press laterally on it.
Associated with?
Cause?
Treatment?
Pemphigus vulgaris
Thymoma, Myasthenia gravis
Auto-IgG to desmoglein 3
Prednisone, then Imuran
Itching and burning, followed by recurrent vesicles and ulcers. Oral or genital.
Associated w/ what other symptoms?
Treatment?
HSV
Encephalitis, seizures, headache
Antivirals
Herpes on finger
Herpetic Whitlow
Grouped vesicles on erythematous base
HSV
Childhood, dew drops on rose petal vesicles, aphthous ulcers, anywhere BUT distal extremities.
Treatment?
Chickenpox (VZV)
Antivirals, antihistamines, VZIg
Subacute/acute tense bullae, older patient, NOT in mucosal
Cause?
Can be caused by?
Diagnosis?
Treatment?
Bullous pemphigoid
IgG antibodies against hemidesmosomes (BPG 1/2)
UV radiation or drugs
Linear immunofluorescence
Prednisone, other
Papules, vesicles, plaques caused by sun exposure. Most common in spring. Skin hardens w/in 30 min of sun exposure.
Common in who?
What is it?
Polymorphous light eruption
Native american descent, females
Type 4 hypersensitivity due to UV-A
VERY pruritic, grouped, symmetric, burning skin blisters. IgA at tips of dermal papillae. Stomach aches and diarrhea when eating gluten.
Cause?
Genetics?
Treatment?
Dermatitis herpetiformes
Gluten-sensitive immune skin disease
HLA-B1, B8, DR8, DRQ
Dapson, gluten-free diet
Targetoid, dull/dusky red macules and vesicular papules on palms and soles. Sloughing of skin. Bilateral and symmetrical. Mucosal involvement common. Positive koebner phenomenon.
Causes?
***Associated with?
Erythema multiforme
Immune response to drugs (sulfa, phenytoin, PCN, allopurinol), foods, sunlight, contacts
HSV
Full thickness skin detachment, fever, tenderness, skin pain, burning. Crinkled surface to skin, positive nikolsky sign, sheets of lost epidermis.
Cause?
Worse in what?
Genetics?
Treatment?
TEN
Cell-mediated hypersensitivity to new drugs
SLE, HIV
HLA-B12
IV fluids, burn unit, steroids, IVIg
