Dermatology Flashcards
Dermatology Terminology
Type Arrangement Location Pattern of distribution Progression over time
Macule
flat circumscribed discoloration
Patch
larger flat lesion of color >1 cm
Papule
Elevated circumscribed lesion
Plaque
broad elevated lesion > 1 cm
Vesicle
circumscribed elevated lesion containing clear fluid
Bulla
larger circumscribed lesion containing fluid >1 cm
Pustule
exudate containing lesion
Nodule
circumscribed elevated lesion involving dermis
Wheal
blanching edematous thin erythematous papule or plaque
Telangectasia
dilation of superficial vessels
Petechia
tiny red macules caused by capillary hemorrhage under skin
DON’T BLANCHE
Purpura
larger purple lesion cause by bleeding under skin
Secondary lesions
Scale - flakes of keratin
Crust - dried remains of fluid
Fissure - linear painful cut in skin
Erosion - slightly depressed lesion (all epidermis lost)
Ulcer - depressed lesion extending into dermis and subq
Excoriation - traumatized superficial loss of skin
Acute Urticaria
HIVES
- rash that comes and goes –> caused by histamine release triggered by allergens
- diagnosis - can blood test for allergens or skin testing
TX - avoid allergens, symptomatic tx
Atopic History
ATOPIC TRIAD
atopic dermatitis (eczema)
asthma
allergic rhinitis
Seborrheic Dermatitis
common in infants, no harm from condition
Tx - baby oil, small brush, frequent shampoo, low potency cream if necessary
Stages of acne
Comedones
- open vs. closed
Inflamed -> papules/pustules
Nodulo-cystic acne
Acne triggers
make-up, mechanical manipulation, occlusion, overzealous cleaning
Chronic Nickel Dermatitis
fairly common skin condition (delayed type IV hypersensitivity)
- reaction requires sensitization
Tx - avoid nickel, self-resolving
Impetigo
staph aureus and GAS
- topical antibiotics (mupiorcin)
- don’t want abscess to form!!
Acute contact dermatitis
vesicles, edema, erythema, pruritic
poison ivy
Topical steroids
Mild - hydrocortisone Intermediate - triamcinolone Potent - betamethasonedipropionate Super potent - clobetasol SE: atrophy, telangectasias, hypopigmentation
Tx for head lice
1% permethrin lotion benzyl alcohol or malathion Lindane Brushing and washing bedding Sealing unwashables in air tight bag
Scabies
itching at night as mite burrows into skin (wrist, elbows, fingers, toes)
- secondary infections are possible
Tx = permethrin at night
Ringworm
caused by fungi –> KOH scraping
lesion: mildly pruritic, annular, well-circumscribed, scaly plaque
Warts and Molluscum Contagiosum
Warts - HPV
Molluscum Contagiosum - virus, looks like wart but has central dimple
Diaper Rash
Irritant dermatitis - prolonged exposure to moisture, friction (tx with zinc oxide)
Diaper Candidiasis - erythematous papule –> satellite lesions (nystatin- anti-fungal)
Bacterial Infection - GAS, cellulitis (oral ABx)
Diaper Rash of serious illness
Zinc deficiency
Langerhans cell histiocytosis - crusty and weepy lesions, diagnose with skin biopsy
Focused History for rash
Duration Rate of onset Location Associated Symptoms FamHx Allergies New exposures Treatments
Key findings for allergic reaction
family history of atopy
recurrent rapid onset and resolution of rash
pruritis
history of response to antihistamines
Urticaria type 1 hypersensitivity
classic pruritic lesion, circumscribed, raised, wheal
- histamine release
- lasts 12-24 hours
- triggered by allergen
Papular urticaria
lesions caused by insect bites
pruritic
Streptococcal infection
rash of scarlet fever
fine, erythematous sandpaper-like rash
Erythema multiforme
acute hypersensitivity
- symmetrical rash that evolves into sharply demarcated wheals –> target lesions
- lesions stay fixed for weeks
Roseola
viral exanthem that follows 3-5 days of febrile illness
HHV-6
- starts on trunk and spreads to extremities
Erythema infectiosum
rash starts on slapped-cheeks and progresses to trunk and extremities
parvovirus B19
Erythema migrans
lesion associated with lyme disease
- red papule that progresses to “target” sign
Rash in infant
Seborrheic dermatitis Eczema Atopic dermatitis Candida rash Psoriasis
Pustular conditions DDx
staph folliculitis
Acne - too much sebum production
hidradenitis suppartive - pustular lesions caused by occlusion of apocrine follicular units (staph, strep pyogenes)
Rosacea - malar and nasal surfaces, worse with certain foods
Perioral dermatitis
Tx of acne
Mild - OTC benzoyl peroxide
Moderate - ABx, BPO
Severe - dermatologist, isotrtinoin
Tx of warts
salicylic acid
