Dermatology Flashcards
Erythematous rash in newborn that SPARES folds…
Contact dermatitis
Erythematous rash in newborn INVOLVING folds…
Candida
Treatment of mild acne
Topical retinoid +/- anti-inflammatory (benzoyl peroxide)
TWO risk of giant congenital nevus (> 20cm predicted adult size)
- Leptomeningeal melanocytosis (CNS involvement) 2. 1-2% risk of developing melanoma (with almost 100% mortality)
First line treatment of scabies
5% permethrin - leave on overnight, treat close contacts, repeat in 1 week
First line treatment of head lice
1% permethrin x 15 mins, repeat one week later
MRSA skin abscess management, < 1 month
- admit - drainage - vancomycin IV
MRSA skin abscess, infant 1-3mos, no surrounding erythema/cellulitis
Septra (if concern for cellulitis, add keflex)
MRSA skin abscess > 3 mos
I&D, send for culture
Name of the skin lesion associated with SJS & TEN
Erythema multiforme
SJS
< 10% skin involvement
Toxic epidermal necrolysis
> 30% skin involvement
Sturge-Weber syndrome
- nevus flammeus (port-wine stain) in V1 - glaucoma - leptomeningeal angioma
Infants with subcutaneous fat necrosis are at risk of
hypercalcemia
If resistant lice (failure of treatment), what can you treat with?
Resultz
If a teen with acne failed topical anti-inflammatory/antibiotics + retinoids; what else can you do?
Doxycycline Anti-androgens (in female patients) Add topical retinoids/benzoyl peroxide
Treatment for tinea capitus
oral terbinafine
Treatment of comedonal acne
retinoids
Treatment of inflammatory acne - mild
retinoids + anti-inflammatory (benzoyl peroxide + antibiotic)
Name the lesion, when they occur, natural history
Halo nevus
May occur during puberty or pregnancy
The central pigmented nevus may disappear and the depigmented area usually repigments
Name the lesion
Spitz nevus
(pink/red, smooth, dome-shaped, firm, hairless papule)
usually < 1cm
local recurrence happens after excision 5% of the time
if suspect melanoma, excise entire lesion
Syndromes associated with the development of melanoma (3)
Familial mole-melanoma syndrome
Dysplastic nevus syndrome
BK mole syndrome
Definition of atypical nevus
When do they appear?
Management
Acquired, 5-15mm, round to oval, irregular margins/colour
Usually develop in puberty
Management: skin exam Q6-12 mos, photos, sun protection, monitoring for melanoma
What meds should you think of if someone has photosensitivity?
NSAIDs
Diuretics
Voriconazole
Antibiotics
What is Nikolsky sign?
Applying slight pressure with the thumb, the skin will wrinkle and the epidermis will separate from the dermis
How does isotrentoin (Accutane) work for acne?
Isotretinoin reduces size and secretion of sebaceous glands, normalizes follicular keratinization, prevents new microcomedone formation, decreases the population of P. acnes, and exerts an anti-inflammatory effect.
How long should someone avoid becoming pregnant after stopping Accutane?
at least 6 weeks
How can you prevent the teratogenic effect of Accutane?
Counsel patients to use 2 forms of birth control, do monthly pregnancy tests
What is this? Why does it occur?
Traction alopecia, common in black school-aged children, due to trauma from tight-braids, headbands (increased risk if chemically-relaxed hair)
Clinical features of Trichotillomania
Pulling, twisting, breaking of hair producing irregular areas of hair loss. Remaining hairs are various lengths and are blunt tipped (from breaking). Scalp appears normal.
Closely related to OCD.
What is this probably caused by?
Trichotillomania
Which cells in the skin are important for making Vit D?
Spinous cells in the epidermis
How would you recognize a Langerhans cell under electron microscopy?
Birbeck granule
What type of hair is on your body? (short, soft, less pigmented)
Vellus
What type of hair is on your head, eyebrows, beard, etc?
Terminal (coarse hair)
What happens to your hair during puberty?
Androgens stimulate pubic, axillary and beard hair to change from vellus to terminal
What is vernix in the newborn?
Produced by stimulation of the fetal sebaceous glands by maternal androgens
AND
desquamated stratum corneum cells
Eccrine sweat glands on the palms and soles respond to…
psychophysiologic stimuli (stress!)
Eccrine sweat glands on the hairy body surfaces respond to…
Body temperature
(Supplied by a sympathetic nerve, sweating is mediated by acetylcholine)
What is an erosion?
Focal loss of epidermis
Heals without scarring
What is an ulcer?
Lesion extending INTO dermis
Heals with scarring
What is a Wood lamp, and what can you use it for?
It emits UV light at 365 nm
Useful for detecting hypopigmented macules (TUBEROUS SCLEROSIS!), certain superficial fungal infections of the scalp
Ways to test for viruses (HSV, VZV)
Tzanck smear
Direct fluorescent assay
PCR
What is this rash?
Malar rash, associated with SLE
This rash appears in a 2 weeks old infant. What is it? What is it associated with?
Neonatal lupus
Manifest during the first weeks to months of life (annular, erythematous, scaly plaques on head/neck/trunk)
May be worsened by light exposure
Due to maternal transfer to anti-Ro/La, levels of these antibodies wane by 6 mos
10% of babies with NL have both 3rd degree heart block and skin findings
Should do labs to check for cytopenias, cholestases etc
Skin findings of Juvenile Dermatomyositis
Heliotrope rash - over eyelides (or racoon eyes)
Gottron papules - over knuckles
Shawl sign - telangiectasians over shoulders
Nail fold telangectasias
Palmar hyperkeratosis “mechanics hands”
Gottron’s papules of Juvenile dermatomyositis
What is this?
What condition is it associated with?
Pyoderma gangrenosum
Ulcerative colitis, Crohn’s disease
What is Sweet syndrome?
A tender, erythematous plaque/nodule on skin associated with
fever
anemia
leukocytosis
biopsy: neutrophilic infiltrate
Rash of a glucagonoma?
Necrolytic Migratory Erythema
When do medication-related skin eruptions occur?
Classic findings?
7-10 days after exposure
Start on trunk, spread peripherally, usually pruritic
May have eosinophilia
Common medications causing drug eruptions?
Penicillins, cephalosporins
Sulfa drugs
NSAIDS
AEDs (carbamazepine, phenytoin, phenobarb)
When does the rash of GVHD occur?
1-3 weeks after transplant, at the time of engraftment
What is DRESS (triad)
Drug reaction with eosinophilia and systemic symptoms
Triad: Fever, rash, hepatitis
Occurs 1-6 weeks after exposure to the medication
30% of patients have eosinophilia
This patient is on septra. He developed neutrophilia, fever and this rash. What is this rash called?
Acute generalized exanthematous pustulosis (AGEP)
Often drug-related (penicillins, macrolines, sulfa drugs)
Non-follicular, sterile pustules with underlying erythema
Associated with neutrophila, fever
Tx: stop drug! May need steroids
Side effects of topical corticosteroids
Atrophy
Striae
Telangectasia
Aneiform eruptions
Purpura
Hypopigmentation
Increased hair growth
2nd line treatment for eczema (does not thin skin)
Elidel, protopic (tacrolimus, pimecrolimus)
Term infant, what is this?
Sebaceous hyperplasia, will disappear within the first few weeks of life
Newborn infant, what is this?
Milia
Superficial epidermal inclusion cysts, contain keratinized material
1-2mm
Pearly white
On face, and in mid-line palate (Epstein pearls)
What are Epstein pearls
Milia on the midline of the palate
Newborn back
Mongolian spots (slate-gray nevus)
Found in people with darker skin tone
Look blue-ish because the melanocytes are arrested in their migration to the epidermis (mid-dermal)
Usually fade during first years of life, do not have malignant degeneration
Erythema toxicum:
firm, yellow-white, 1- to 2-mm papules or pustules with a surrounding erythematous flare
Peak incidence day 2 of life
Smear shows eosinophils
Newborn rash
Three types of lesions
Transient neonatal pustular melanosis
THREE TYPES OF LESIONS:
- Pustules (+PMNs) w/ NO erythema
- Ruptured pustules (colarette)
- Hyperpigmented macules (may persist up to 3 months!)
Rash that starts at 2-10 months of age, more common in black males
Discrete erythematous papules / vesicles / pustules
Very pruritic
On hands, soles
Episodic, lasting 7-14 days
Cyclic x 2 yrs
Infantile Acropustulosis
Aplasia Cutis (developmental absence of skin)
multiple or solitary, non-inflammatory, well-demarcated ulcers
may have collar of hair
associated with syndromes/diseases: Patau (Trisomy 13), epidermolysis bullosa
Dyskeratosis Congenita - TRIAD
Reticulated hyperpigementation of th eskin
Dystrophic nails
Mucous membrane leukoplakia
(also: bone marrow failure, increased squamous cell carcinoma!)
Causes of Erythema Multiforme
HSV
Develops 10-14 days after onset of HSV
What is this? What is it associated with?
Erythema multiforme
(Target lesions)
Associated with HSV
Lesions typically resolve in 2 weeks
Does NOT progress to SJS
Treatment of Erythema Multiforme?
Supportive - topical emollients, anti-histamines, NSAIDs
Avoid steroids (no evidence, may make sxs worse)
Causes of Stevens-Johnson Syndrome
Mycoplasma pneumoniae
Drugs - sulfa, NSAIDs, antibiotics, AEDs
Genetic predisposition - Han Chinese (certain HLA types) develop this after receiving carbamazepine
SJS vs TEN
Rash + involvement of > 2 mucous membranes (eyes, GI, GU, resp) forming bullae, ulcers, hemorrhage
SJS < 10%
TEN > 10% + skin tenderness, no target lesions
MUST consult ophtho - scarring can lead to vision loss
Infection is the leading cause of death
What is this?
Staph scalded skin syndrome
How do you differentiate TEN from staph scalded skin?
SSS - Nikolsky sign is widespread, perioral crusting/erythema, sparing of intra-oral mucous membranes (can have crusted lips, conjunctivitis)
TEN - Nikolsky sign over erythematous skin, hx of drug ingestion
(also, BIOPSY!)
Do the bullae in staph scalded skin grow any bugs?
nope! they are sterile - the separation of the epidermis is due to toxin production
Treatment for staph scalded skin
IV cloxacillin + clindamycin (to stop production of toxins)
Medications causing pseudoporphyria (photosensitivity reaction)
NSAIDs
Tetracyclines
Diuretics
Sulfa drugs
Baby with suspected PHACE syndrome. What other tests should you do to work-up?
ECHO - can have cardiac abnormalities like coarct
Ophtho exam - eye anomalies (glaucoma, cataracts)
MRI brain - posterior-fossa abnormalities, dandy-walker malformation
these lesions developed in a female newborn
the vesicles were high in eosinophils, and the systemic WBC shows eosinophilia
what condition should you think of?
Incontinentia pigmenti
x-linked dominant
due to mutation in IKK-gamma/NEMO gene
