Dermatology

Question 1

Atopic Dermatitis: Infantile Phase

Answer 1

starts 0-6mo, lasts 2-3 years. d/t mutations in filaggrin. red, pruritic papule, plaques that ooze and crust. Over cheeks, forehead, scalp, trunk, extensor surfaces. Symmetrical.

Question 2

Atopic Dermatitis: Childhood phase

Answer 2

4-10 years. Dry, papular, intensely pruritic; circumscribed scaly patches on wrists, ankles, A/C, popliteal fossae that can easily get infected. Chronic areas may show lichenification. Cracking, dryness, scaling of palms and plantar surfaces also common. 75% kids resolve by 14 years; rest have chronic adult

Question 3

Atopic Dermatitis: Adult phase

Answer 3

begins age 12 continues. flexor areas of arms, neck, legs, and sometimes dorsal surfaces of hands/feet. lichenifcation may be marked. Dryness, perifollicular scales on extensor surfaces, hyper linearity of palms, changes in pigment. Susceptible to s. aureus. at risk for skin infections.

Question 4

Pityriasis Alba

Answer 4

poorly defined, hypo pigmented, round or oval scaly patches 2-4cm on face and extremities; don’t enhance with Wood lamp. More noticeable in spring/summer (don’t tan). Asymptomatic and resolves spontaneously in months to years. Use moisturizers.

Question 5

Atopic Dermatitis Patho

Answer 5

Unknown but may be immunologic due to elevated igE; may also be hereditary. Pruritic worsened with dry skin, fragrance products, wool fabrics, foods, infectious agents, etc.

Question 6

Atopic Dermatitis Treatment

Answer 6

Eliminate predisposing factors; Hydration and lubrication; antipruritic agents; intermittent topical steroids. Pimecrolimus and tacrolimus ointments may help (>2y, risk cancer). Monitor for infection to treat quickly. Hyperdiluted bleach bath each week can prevent that.

Question 7

Dishidrotic Eczema

Answer 7

severely pruritic, chronic, recurrent, vesicular eruption of palms, soles, and lateral aspects of fingers/toes; symmetrical. “tapioca” papule. Frequent exposure to water, soaked shoes, or chemicals may trigger or exacerbate. May need higher potency steroids.

Question 8

Nummular Eczema

Answer 8

acute papulovesicular eruption, coin shaped. pruritic, well-circumscribed, round to oval, red, scaly patches with 1-3mm vesicles. on extensor thighs/abdomen. Can get excoriated and crust. Can be resistant to therapy.

Question 9

Juvenile plantar/palmar dermatosis

Answer 9

“sweaty sock syndrome”. toddlers/ school age. Chronic, red, scaly patches with cracking and fissuring on balls of feet and big toes, and pads of fingertips/palms. Triggered by excessive sweating followed by drying. Tx: emollients and intermittent topical steroids.

Question 10

Lip-Licking and Thumb-Sucking Eczema

Answer 10

repeated wetting/drying > eczema around mouth. Explore stress.

Question 11

Seborrheic Dermatitis

Answer 11

erythema, scaling on hair-bearing and intertriginous areas. In infants, can be cradle cap; in adolescents, may look like dandruff. May involve Candida/Pityrosporum. Nonpruritic and mild, can clear spontaneously but have residual hypo pigmentation for a few months.

Question 12

Pityriasis Rosea

Answer 12

benign, self-limited, at any age but common adolescents/young adults. prodrome of malaise, headache, mild s/s. Eruption with herald patches: large, isolated, oval lesions that are pink and slightly scaly; can clear centrally. 5-10 days later, small oval lesions appear, frequently on trunk but also extremities. somewhat raised, vary in pigmentation. peaks in a few weeks then fades over 8w. Oral EES/doxycycline.

Question 13

Contact Dermatitis

Answer 13

Inflammatory reaction in skin from direct contact with irritants. Can be acids, alkalis, hydrocarbons. Rash is acute, well demarcated redness, crusting, and/or blisters. Allergic contact dermatitis is t-cell mediated; can be acute or if they’ve waited chronic with scaling, lichenification, pigment changes. occurs after 1-2w sensitization time. type IV hypersensitivity

Question 14

Tinea corporis

Answer 14

fungal infection of non-hairy body skin. “ringworm”. Pruritic, annular lesions with central clearing and active border of micro vesicles that can rupture and scale. Patches can expand. Contagious. Autoinoculation from patch to other sites. KOH + diagnosis. Tx: itraconazole topical antifungals; if widespread, oral griseofulvin. Never treat with combo steroid/antifungal.

Question 15

Tinea Pedis

Answer 15

athletes foot; fungal infection in web spaces between toes. common adolescence. can have scaling/fissuring, vesiculopustular lesions and maceration. burning and itching. tx with topical antifungals and powders, drying feet post bath, wearing cotton socks, shoes or sandals.

Question 16

Tinea Versicolor

Answer 16

multiple small, oval, scaly patches 1-3cm in guttate or raindrop pattern on upper chest, back, proximal portions of upper extremities. Asymptomatic or mild pruritic. Various colors. tan to salmon-pink glow with Wood lamp. Topical anti yeast agents like selenium for tx. or anti fungal cream.

Question 17

Diaper Dermatitis

Answer 17

do frequent diaper changes, gentle cleansing, thick lubricants/ zinc oxide paste. Persistent may be due to other disorders like contact with dyes or wipes, candidiasis, etc.

Question 18

Candidal diaper dermatitis

Answer 18

bright red with sharp borders, pinpoint satellite papule and pustules; often also oral thrush. common post antibiotics. anti fungal cream.

Question 19

Staphylococcal diaper dermatitis

Answer 19

thin walled pustules on a red base, rupture rapidly and dry > collarette of scaling around denuded red base. oral/topical antibiotics

Question 20

Psoriatic diaper dermatitis

Answer 20

red scaling eruption in diaper area, looks like severe seborrheic diaper dermatitis. no silverly scale due to moistness. Rash persists for months only at diaper area. Skin biopsy confirms

Question 21

Insect Bite Management

Answer 21

topical steroids, using bug spray <30% DEET; oral antihistamines. Anaphylactic management with epilepsy, antihistamines, steroids, ICU etc

Question 22

Scabies Management

Answer 22

permethrin cream to patient, household members, and close contacts. Cleansing all dirty bedding twice one week apart. oral antipruritics and topical steroids for a while.

Question 23

Acne Patho

Answer 23

more common puberty. Open Comedones = blackheads, closed comedones = whiteheads. Androgens stimulate sebum production which feeds Propionibacterium acnes, causes pustules with fatty acids, pops and spreads etc. Cystic acne has nodules and cysts over face, chest, and back and can cause scarring.

Question 24

Acne Treatment

Answer 24

mild to moderate: retinoids, benzoyl peroxide, antibiotics. Moderate to severe papulopustular: oral antibiotics with topicals. Isotretinoin for acne that is recalcitrant to other regimens or is moderate to severe, scarring, and cystic. Refer if not responding to treatment in 2-3 months

Question 25

Molloscum

Answer 25

contagious d/t pox virus. Sharply circumscribed dome-shaped papule with waxy surfaces. Can be pruritic. Pinpoint then enlarge to 5cm. Mostly on trunk/face, axillae and genital area. Linear. Curd-like core can be expressed. Asymptomatic and spontaneous remission in 2-3 years. Symptomatic, at home topical antiviral therapy can be done.

Question 26

Milia

Answer 26

1-2mm whitish-yellow papule on neonatal faces. Firm, not easily denuded by pressure. Can be persistent but can resolve spontaneously after months to years. No apparent cause.

Question 27

Mongolian Spots

Answer 27

flat, slate gray to bluish-black, poorly circumscribed. mostly on limbo-sacral area and buttocks but can be anywhere. 1-10 cm. single or multiple; most black and asian babies have some. usually fade by 7 years old.

Question 28

Erythema Toxic Neonatorum

Answer 28

benign, self limited, asymptomatic; in up to 1/2 term babies. start 1-2 days out and disappear on 10th day. flea-bitten dermatosis of newborn, intense redness with central papule or pustule. palms, soles usually spared. high eosinophils. no treatment necessary.

Question 29

Sebaceous Gland Hyperplasia

Answer 29

multiple 1-2cm yellowish-white papule over nose of full term infants, fade by 4-6months. due to maternal androgens.

Question 30

Cutis Marmorata

Answer 30

netlike mottling of skin due to chilling, goes away when rewarmed. symmetrical. usually abates at 6months but may last longer in fair skinned babies.

Question 31

Nevus

Answer 31

“stork bite” “salmon patch”. nape of neck, on forehead, upper eyelids, lower back more apparent when baby cries but don’t bulge. fade over first year of life. If bulges with valsalva, concern for sinus pericranii or AVM and needs radiology promptly.

Question 32

Melanoma

Answer 32

Mal develop in existing nevus; increased exposure to UV light contributes to increase. Check: Asymmetry, Border irregularity, Color change, Diameter greater than a pencil eraser, Evolution (change, and most important). Needs prompt excision.

Question 33

Vitiligo

Answer 33

partial to complete loss of pigmentation; we’ll-demarcated macule and patches around eyes, mouth, genitals, elbows, hands, and feet. enhance dramatically under Wood lamp. may have halo nevi. spontaneous but slow regimentation > speckled appearance. melanocytes are destroyed by autoimmune reaction.

Question 34

Albinism

Answer 34

inherited, X-linked or autosomal recessive. no trace of pigment: white hair, pink white skin, translucent or blue irises. nystagmus common and poor vision. tyrosinase + OCA may develop some pigment with age. high risk skin cancers.

Question 35

Cafe-au-lait Macules

Answer 35

can be indicator of neurofibromatosis type 1. smaller, oval, smooth borders and associated with axillary/inguinal freckling. large/segmental/jagged borders more likely with mcCune-Albright syndrome. no syndrome usually <4 and small sized.

Question 36

Erythema Multiforme

Answer 36

acute hypersensitivity syndrome commonly triggered by HSV. symmetrical and can occur anywhere, commonly dorsal of hands/feet and extensor surfaces arms/legs. dusky red macule or red wheels that evolve to iris or target shaped lesions. may have diffuse urticaria, but usually less pruritic if at all. can become painful/persistent. may develop bull. lasts 1-3 weeks. self-limited, mild systemic s/s.

Question 37

Tinea Capitis

Answer 37

fungal infection of hair causes shaft breakage, ringworm. T. Tonsurans mostly responsible. mild redness/scaling to salt and pepper look of hair. sometimes annular. can have crusts. can make scarring/permanent hair loss. KOH +. oral anti fungal for 6 weeks.

Question 38

Hemangioma

Answer 38

Appears by 2-3 weeks; pale, telangiectatic, or bright red nodule. Proliferate and then eventually involute by 10years old. Involution starts at 1-2years with greying and flattening. Tx: propranolol in proliferation stage. If on eye/mouth/diaper/airway, ulcerating, multiple, large, or quick growth, refer to derm

Question 39

Burns

Answer 39

Often due to scalding liquid in infancy and flames in children. Use sunscreen, smoke alarms, hot water temp max 120, pot handles away from stove, don’t leave cooking food unattended, fire escape plan, caution with table runners or cloths, barriers before fireplaces, no unattended space heaters, caution with cords to hot things, and protected plugs.

Question 40

Burns first aid

Answer 40

Minor burns in tepid water, no oil/butter/mayo, chemical burns rinse cold water and flush skin 20 min

Question 41

Cellulitis

Answer 41

Localized skin infection of dermis and subQ. More common in DM/immunocompromised. Often d/t strep pneumo/staph aureus. Buccal/joints d/t h. Flu 3mo-3years. Edema within 24h of bite is inflammatory, 48-72h infectious. Recent sore throat possible. S/s fever, malaise, irritable, pain, vomiting, chills. Red, indurated, tender, swollen, warm, poorly marked skin area. Complications include TSS and necrotizing fasciitis

Question 42

Cellulitis treatment

Answer 42

CBC/BCX if febrile, ill, or <1 year. Treat empirically. Aspirate can be done. Needs abx, hospitalization if Ill, peri- orbital, or young. If strep, penicillin. If allergy, 3rd gen. Cephalosporin or mupiricin topical. Staph: Bactrim or doxy. MRSA: clinda. H. Flu: amoxicillin, methicillin or 3rd gen cephalosporin. F/u in 24h until recovered.

Question 43

Impetigo

Answer 43

2 forms: nonbullous with honey crusts, and bullous. D/t strep pyogenes, staph aureus, or MRSA. Nonbullous with staph most common and after trauma. Bullous sporadic. Colonization days to months prior to infection. Risks: poor hygiene, summer, humid hot. Papules > lesions or bullae burst honey crust. Bullous: thin walled flaccid burst and leave varnish. Found mostly everywhere but trunk. Tx: topical or if major amoxicillin etc.

Question 44

Foliculitis

Answer 44

Infection of hair follicle. Risk: maceration, moist environment, poor hygiene, occlusive emollients, prolonged submersion in contaminated water. More common in males. S/s: itching, hot Tub exposure, red papules inflammed base. Often everywhere but chest. Itchy, deep red to purple, most dense in swimsuit area 8-24 hours post exposure. Tx: soap/water and warm compresses. Keratolytics, can do topical abx, if large and fluctuant drain. Dicloxaxillin 7-10days severe cases. F/u 1 week. Resolves 5-14d but Can recur 3mo.