Week 5 Flashcards
1
Q
Etiology: pityriasis rosea
A
reactivation of HHV-7, primary infx w/ HHV-6, HHV-8, H1N1
2
Q
SSx: pityriasis rosea
A
prodrome possible (HA, malaise, pharyngitis), some itching but usu asx; oval, minimally elevated scaling papules/plaques; “Herald” patch; “Christmas tree” distribution.
3
Q
Age: pityriasis rosea
A
young adults
4
Q
Distribution: pityriasis rosea
A
trunk
5
Q
DDx: pityrias rosea
A
tinea corporis, tinea versicolor, drug eruptions, psoriasis, syphilis
6
Q
What is a herald patch?
A
A larger lesion seen in pityriasis rosea
7
Q
Etiology: lichen planus
A
idiopathic, possible Hep C role
8
Q
SSx: lichen planus
A
angular, violaceous papules 2-4 mm; oral lesions, severe itching; new lesions are pink/white that change to PPPP, lacy reticulated pattern of whitish lines; lesions can become thick/red
9
Q
Distribution: lichen planus
A
ankles, wrists, pubic region, lips, mouth
10
Q
Dx: lichen planus
A
H&P, bx (accumulation of PMN’s, T-cell mediated cytotoxic rxn against basal cell keratinocytes), Hep C antibodies (16%)
11
Q
DDx: lichen planus
A
leukoplakia, candidiasis, herpes stomatitis, carcinoma, aphthous ulcers, erythema multiforme, psoriasis, discoid lupus, drug eruptions
12
Q
Etiology: drug eruptions
A
any drug but common drugs include penicillin, sulfonamides, quinidine (antibiotics)
13
Q
SSx (exanthems): drug eruptions
A
most common, antibiotic cause; mild pruritic, measles-like rash w/ macules/papules. Symmetric distribution on trunk/extremities (can occur on palms/soles/mucus membranes). Not common in infants. Hx - include EBV, CMV for amoxicillin
14
Q
SSx (urticaria): drug eruptions
A
common, IgE-mediated-antibiotic cause, non-IgE-NSAID cause; pruritus, burning of palms/soles; systemic sx (flushing, fatigue, tongue numbness, bronchospasm, n/v, palpitations, hypotension)
15
Q
SSx (pustular): drug eruptions
A
“acne” on arms and legs
16
Q
SSx (fixed drug eruptions): drug eruptions
A
circular, recurring at same site; erythematous patch/plaque/bulla/erosion; occurs hrs after ingestion; many drugs involved
17
Q
Etiology: erythema multiforme
A
drugs, infx (HSV/mycoplasma), immunization, autoimmune dz, malignancy
18
Q
Comparison: minor vs major erythema multiforme
A
minor - w/o mucosal involvement, major - w/ mucosal involvement (ano genital, oral, ocular)
19
Q
SSx: erythema multiforme
A
onset 3-5 days, resolves within 2 wks; can recur; erythema/edema bullous lesions; sudden onset on face/extremities; symmetrical annular lesions (target); pruritic/painful; systemic sx possible (fever, weakness, malaise); mild to severe
20
Q
Distribution: erythema multiforme
A
dorsal/palmar hands, soles, forearms, feet, face, elbows, knees, penis/vulva, mucus membranes
21
Q
Population: erythema multiforme
A
50% < 20 yo, M > F
22
Q
DDx: erythema multiforme
A
urticaria, drug eruptions, bullous pemphigoid, pemphigus, dermatitis herpetiformis, aphthous stomatitis, herpes stomatitis
23
Q
Etiology: erythema nodosum
A
infx, drugs, malignancy, inflammatory/granulomatous dz (sarcoidosis)
24
Q
SSx: erythema nodosum
A
indurate, painful nodules resembling bruises, color changing, successive crops of nodules; pretibial; systemic sx (fever, malaise, joint pain); resolution in 6 wks
25
Population: erythema nodosum
any age, but peaks at 20-30, F > M (6x)
26
Dx: erythema nodosum
H&P, Bx, ESR, CRP, ANA, CBC, chest x-ray, ASO-titer or pharyngeal cultures (GABHS)
27
What is miliaria?
heat rash; accumulation of sweat beneath eccrine sweat glands resulting in obstruction of kerating at level of stratum corneum.
28
SSx: miliaria
pruritic, small/red papules, pustules occasionally
29
Population: miliaria
more common in kids/babies
30
Etiology: cellulitis
S. aureus, GAS (most common in adults); Hib, GAS, S. aureus (children); immunocompromised; IV drug use
31
SSx: cellulitis
local erythema, heat, edema, tenderness w/ lymphangitis and regional LA; systemic (fever, chills, tachycardia, HA, hypotension, delirium)
32
Distribution: cellulitis
lower legs (adults); cheeks, periorbital, head, neck (children)
33
DDx: cellulitis
DVT, gout, CPPD, septic arthritis, stasis dermatitis, insect bite, erysipelas
34
What is a cutaneous abscess?
localized collection of pus under the skin
35
SSx: cutaneous abscess
painful/tender/indurated/erythematous; varying size (1-3 cm); concomitant: local cellulitis, lymphangitis, LAD, fever
36
What is erysipelas?
superficial cellulitis with dermal lymphatic involvement (streaking)
37
Etiology: erysipelas
GAS, immunocompromised
38
SSx: erysipelas
shiny/indurated/well-demarcated plaques; high fever/chills/malaise/LAD or no systemic sx; may see vesicles/bullae/petechiae w/ itching/burning/pain; red/painful streaks along lymph; sudden onset
39
Complications: erysipelas
scarlet fever, fat necrosis, gangrene
40
Distribution: erysipelas
legs (most common), face
41
DDx: erysipelas
herpes zoster, contact dermatitis
42
What is erythrasma?
superficial intertriginous infx w/ Corynebacterium
43
SSx: erythrasma
pink/brown patches on genitals, scaling/fissuring/maceration, patches on trunk
44
Distribution: erythrasma
toe webs, between fingers, genitals, trunk
45
Dx: erythrasma
coral red fluorescence w/ Wood's lamp, no hyphae, skin scraping w/ KOH
46
DDx: erythrasma
tinea, candida
47
Etiology: folliculitis
S. aureus, fungal, persistent trauma, systemic corticosteroids
48
SSx: folliculitis
pustule/inflammatory nodule surrounding a hair follicle; superficial or deep; mild itching/pain; abrupt onset; may be chronic
49
What is "hot tub" folliculitis?
caused by pseudomonas following exposure to contaminated water; high rate of infx in kids; occurs 8 hrs - 5 days post-hot tub; trunk/groin
50
Dx: folliculitis
H&P, KOH to r/o dermatophyte
51
DDx: folliculitis
acne, follicular keratosis
52
SSx: furuncle
acute/tender/swollen/painful nodule w/ central necrosis and pus d/c; mb recurrent; can rupture leaving violaceous scar
53
Etiology: furuncle
staph. aureus
54
Population: furuncle
uncommon in children
55
Dx: furuncle
H&P, culture to r/o MRSA
56
What is a carbuncle?
cluster of furuncles w/ multiple draining orifices
57
Distribution: carbuncle
neck, face, breasts, buttocks
58
Etiology: impetigo
S. pyogenes, S. aureus; warm/moist climate, poor hygiene
59
SSx: candidiasis
intertriginous, erythematous, well-demarcated, pruritic patches of varying sizes/shapes; glistening surface; satellite lesions around main area
60
SSx: impetigo
clusters of vesicles/pustules that rupture and develop honey-colored crust; scaling borders; satellite lesions; regional LA; mb pruritic
61
Distribution: impetigo
face, shins, extensor surface of forearms
62
Age: impetigo
common in children
63
DDx: candidiasis
dermatophytoses, allergic derm, herpes, molluscum, psoriasis, contact derm, strep cellulitis, seborrheic derm
64
Dermatophytoses - tinea cruris ("jock itch")
Etiology: obesity, diabetes, immunocompromised; SSx: erythematous/well-demarcated patch on inner thigh(s); M > F; Dx - KOH prep; DDX - contact derm, psoriasis, Candida, erythrasma, seborrheic derm
65
DDx: impetigo
atopic derm, contact derm, perioral derm, HSV, HZV, tinea
66
Dermatophytoses - tinea capitis
Children most affected; hair loss, kerion (boggy/swollen/oozing plaque, immune rxn); Dx - KOH shows hyphae Wood's lamp: silver-blue; DDx - psoriasis, seborrheic derm
67
Etiology: candidiasis
immunosuppression, sugar dysregulation, antibiotics, oral contraceptives
68
What is dermatophytoses?
fungal infx of keratin in skin/nails
69
Dx: dermatophytoses
H&P, Wood's lamp, skin scraping, KOH prep
70
Dematophytoses - tinea corporis ("ringworm")
SSx - pruritic, circular/oval, erythematous, scaling patch/plaque spreading centrifugally. central clearing with active advancing red/raised border; Dx - KOH shows hyphae, culture; DDx - pityriasis rosea, drug eruptions, nummular derm, erythema multiforme, tinea versicolor, psoriasis
71
What is a dermatophytid reactions ("id" rxn)?
distant site inflammatory rxn during fungal infx; sterile
72
Distribution: tinea versicolor
trunk, proximal upper extremities
73
Dx: tinea versicolor
direct microscopy ("spaghetti and meatballs", broad hyphae and clusters of budding cells), Wood's lamp (yellow to yellow-green fluorescence)
74
DDx: tinea versicolor
vitiligo, pityriasis rosea, tinea corporis, seborrheic derm, erythrasma
75
Etiology: cutaneous larva migrans ("creeping eruption")
hookworm larva from dog/cat excrement
76
SSx: cutaneous larva migrans
intense puritus, erythema, papules at site of entry; winding tail of inflammation (serpiginous, usu 3 wks after exposure)
77
Distribution: cutaneous larva migrans
feet/ankles, buttocks, backs of legs/back
78
DDx: cutaneous larva migrans
scabies
79
SSx: lice (pediculosis)
severe pruritus, mb excoriations, red puncta, gray/white nits on hair shaft, brown specks of excrement
80
Dx: lice
demo of living lice in wet hair using fine-toothed comb; fluorescence under Wood's lamp
81
DDx: lice
seborrheic derm, impetigo, insect bites
82
Distribution: scabies
hands, arms, feet, gluteal fold, axilla, back of knees
83
Dx: scabies
burrows are pathognomonic, H&P
84
DDx: scabies
insect bites, fungus, eczema, folliculitis, impetigo
85
SSx: molluscum contagiosum
smooth/flesh-colored/hard umbilicated dome; cheesy core; asx; 6-9 mos
86
Age: molluscum contagiosum
any; most common in 3-9 yo
87
Distribution: molluscum contagiosum
face, arms, chest, genitals
88
Dx: molluscum contagiosum
H&P, bx ("molluscum bodies" in keratinocytes)
89
DDx: molluscum contagiosum
folliculitis, milia, verrucae
90
What is acanthosis nigricans?
thickened, velvety hyperpigmentation of flexural surfaces; asx
91
Distribution: warts
hands, knees, genitalia, feet
92
SSx: varicella
prodrome (malaise, chills, HA, sore throat, anorexia, dry mouth), rash, pruritus, macules/papules/pustules/crusts/vesicles
93
Distribution: varicella
begins on trunk, spreads to face/extremities
94
Prognosis: varicella
infectious 2 days before lesions until all lesions crust over
95
Dx: varicella
H&P, characteristic rash, culture/Tzanck smear
96
DDx: varicella
other viral dz, contact derm, zoster, folliculitis, impetigo
97
Etiology: chickenpox
primary infx with varicella (HHV-3)
98
Dermatophytoses - tinea pedis ("athlete's foot")
intense pruritus, erythematous vesicles/bullae between toes or on soles; unilateral/bilateral; Dx - skin scraping; DDx - dyshidrotic eczema, contact derm, psoriasis
99
SSx: tinea versicolor
asx hypopigmented/hyperpigmented macules w/ scaling patches
100
SSx: scabies
burrows w/ fine/wavy lines in the skin covered by lichenified skin; intense pruritus, esp. at night; erythematous papules w/o many burrows
101
Etiology: molluscum contagiosum
pox virus
102
What is leser-trelat?
sudden eruption of many seborrheic keratosis (visceral adenocarcinoma)
103
Dx: herpes zoster
pathognomonic rash, Tzanck smear, culture
104
Etiology: shingles
latent varicella (HHV-3) infx
105
Distribution: herpes simplex
mouth, eyes, genitals
106
SSx: herpes simplex
single/clustered vesicles, systemic sx (fever, malaise, myalgia, HA, LA), prodrome (tingling), vesicles which rupture and ulcerate, painful
107
DDx: rubeola infantum
measles, rubella, enteroviral infx, erythema infectiosum, scarlet fever, drug allergy
108
SSx: rubeola infantum
10 day incubation, 3-5 days of high fever, febrile convulsions, rash (30%), LA
109
Distribution: rubeola infantum
prominent macular rash on chest/abdomen, less so on face/extremities
110
Etiology: hand foot and mouth dz
coxsackie virus
111
DDx: herpes zoster
before rash (MI, pleurisy, migraine), after lesions (HSV, primary varicella)
112
What is herpetic whitlow?
infx of distal phalanx w/ painful, swelling lesion
113
Distribution: hand foot and mouth dz
buccal mucosa, tongue, palms, soles, buttocks, genitals
114
Population: hand foot and mouth dz
< 5 yo most common
115
DDx: hand foot and mouth dz
varicella, herpes, herpangina, aphthous stomatitis
116
Etiology: measles (rubeola)
paramyxovirus
117
Etiology: roseola infantum
HHV-6 or 7
118
DDx: herpes simplex
impetigo, eczema, zoster, hand/foot/mouth dz, aphthous stomatitis
119
SSx: herpes zoster
latent in nerve root, erupts along dermatome, radicular pain/itching for 2-3 days followed by herpetic rash; systemic sx
120
Dx: measles
koplik spots/rash, anti-measles IgM/IgG (four-fold increase), CBC (leukopenia, T-cell cytopenia, thrombocytopenia), CXR (interstitial pneumonitis)
121
SSx: hand foot and mouth dz
vesicular eruption of skin/mucosa, fever, myalgia, LA, abd pain, poor nursing, painful lesions in mouth
122
Distribution: herpes zoster
along dermatome, never crosses midline
123
Distribution: rubella
face first, spreads to trunk/extremities
124
DDx: measles
during prodrome (many), during rash (scarlet fever, rubella, drug rxns, roseola, erythema infectiosum, rocky mtn spotted fever, infx mononucleosis, kawasaki dz, TSS)
125
SSx: measles
prodrome (fever, conjunctivitis, photophobia, koplik spots, cough, coryza), rash 2-3 days later (maculopapular, blanching), 5-6 days
126
What are Koplik spots?
1-3 mm white/gray/blue elevations w/ erythematous base on buccal and vaginal surface; prodrome of measles
127
DDx: rubella
measles, scarlet fever, drug rashes, erythema infectiosum
128
Distribution: measles
begins on face, spreads to neck, trunk, extremities
129
Etiology: vitiligo
idiopathic; associated w/ thyroid dz, pernicious anemia, SLE, addison's dz
130
SSx: rubella
mild incubation - 14-21 days, brief prodrome (fever, malaise), faint rash (maculopapules, petechiae on soft palate), asx to mild dz
131
Dx: vitiligo
exam, Wood's lamp, thyroid function, CBC, fasting blood glucose
132
What is trichotillomania?
psychological disorder related to OCD where pt pulls out hair
133
Dx: alopeica
ratio of anagen and telogen haris
134
What is hirsuitism?
excess hair in females in areas that are not normally hairy
135
DX: hirsuitism
serum free/total testosterone, DHEA-S, FSH, LH, prolactin, TSH
136
SSx: vitiligo
hypopigmented areas, well-demarcated, often symmetric, white w/ no scale, focal spots to entire body segments
137
DDx: vitiligo
tinea versicolor, post-inflammatory hypopigmentation, chm-induced depigmentation, pityriasis alba
138
Risk factors: onychomycosis
swimming, tinea pedis, psoriasis, diabetes, immunodeficiency, genes, FHx
139
SSx: onychomycosis
asx patches of white/brown/yellow discoloration and deformity of nails; thickening
140
DDx: onychomycosis
psoriasis, eczematous conditions, senile ischemia, trauma, lichen planus, iron deficiency
141
Distribution: dermatofibroma
lower extremity
142
What is melasma / chloasma?
macular hyperpigmentation of face, usu in pregnant women, dark-skin
143
Etiology: alopecia
autoimmune, genes, infx, drugs (chemo), vaccines, stress, pregnancy
144
What is onychomycosis?
fungal infx of nail plate/bed
145
SSx: dermatofibroma
epidermal thickening/hyperpigmentation, small red/brown papule; no growth; usu solitary, non-tender, "dimple sign"
146
SSx: epidermal cyst
contains keratin, flesh-colored/moveable nodule, central punctum, non-tender
147
Distribution: epidermal cyst
face, base of ears, trunk
148
What is a keloid?
excess fibroblastic proliferation following trauma/scarring
149
SSx: keloid
elevated/shiny/firm/protuberant nodule at site of injury
150
What is a lipoma?
subQ nodule of adipocytes
151
Distribution: lipoma
trunk, forearms, neck
152
SSx: lipoma
rubbery/moveable/asx nodule, overlying skin normal, slow-growing
153
DDx: lipoma
epidermal cyst
154
What are nevi?
circumscribed, oft pigmented/flesh-colored macules/papules/nodules composed of melanocytes
155
DDx: nevi
melanoma, seborrheic keratosis, skin tag, wart
156
Morphology: atypical/dysplastic nevus
irregular/pigmented nevus, indistinct borders, genetic, usu appear in multiples, greater risk for melanoma, > 6 mm
157
Distribution: seborrheic keratosis
trunk, face, upper extremities
158
DDx: seborrheic keratotis
warts, nevi, melanoma, pigment basal cell carcinoma
159
DDx: acrochordon
warts, nevi, neurofibromas
160
Distribution: acrochordon
neck, axilla, groin, under breasts, eyelids, perianal skin tags common in Crohn's
161
What is the most common tumor of infancy?
hemangioma
162
Distribution: hemangioma
head and neck
163
Morphology: hemangioma
bright red, raised, if deep can look violaceous
164
What are nevus flammeus and port-wine stain?
capillary malformations present at birth
165
Population: nevus araneus
increases in pregnancy and chronic liver dz
166
Morphology: cherry angioma
freq round, smooth, dome-shaped, bright to dark-red lesions; do not blanch, 1-4 mm
167
DDx: pyogenic granuloma
melanoma or malignant tumor
168
SSx: pyogenic granuloma
yellow-to-deep red, fast-growing, friable nodule, does not blanch
169
Distribution: basal cell carcinoma
face, neck, scalp most common; shoulders, arms
170
DDx: basal cell carcinoma
nevi, seborrheic keratosis, dermatitis, scars, molluscum, SCC
171
Morphology (nodular): basal cell carcinoma
starts as papules, slow-growing into "rodent ulcer" (shiny pearly border, telangiectasia, central ulcer), alt crust/heal
172
DDx: dermatofibroma
nevi, basal cell carcinoma
173
DDx: epidermal cyst
sebaceous cysts, lipoma, if firm r/o malignancy, if strange locations r/o Gardner's syndrome (colon cancer)
174
Population: keloid
africans/asians most common
175
Population: basal cell carcinoma
more common > 40
176
Comparison: lentigo vs freckles
lentigo - increased melanocyte density
| freckle - increased melanin production
177
Warning signs that previously benign lesion becoming malignant melanoma
change in size, shape, color; new lesion, inflammation, sensory change, crusting/bleeding
178
Morphology: seborrheic keratosis
warty, well-circumscribed, hyperpigmented lesions, horn cysts, dark keratin plugs
179
Morphology: nevus flammeus and port-wine stain
flat pink blanchable marks (nevus flammeus), reddish-purple appearing anywhere and becoming darker (port-wine stain)
180
Morphology (superficial spreading): malignant melanoma
Most common melanoma; women's legs / men's torsos; variegated/indurated plaque w/ irregularly raised border
181
Location (acrolentiginous): malignant melanoma
areas of no hair (soles, palms, nails)
182
DDx: SCC
actinic keratosis, seborrheic keratosis, basal cell carcinoma
183
SSx: acrochordon
asx skin tags, flesh-colored tumor, pedunculated, soft
184
Morphology (lentigo-maligna): malignant melanoma
face or sun-exposed, tan/brown macule w/ darker spots, irregular border, plaque w/ raised edges/colored spots, in situ for yrs
185
Morphology (nodular): malignant melanoma
dark, protuberant papule/plaque varying in color; fast growing
186
DDx: malignant melanoma
basal cell carcinoma, seborrheic keratosis, benign nevi/lentigo, dermatofibroma, warts
187
SSx: SCC
usu on sun-exposed areas; usu starts as red papules/plaque w/ rough/scaly surface; occ cutaneous horns; ulcerate/bleed
