Derm

Question 1

Acne Vulgaris definition, sx, dx, tx

Answer 1

Inflammatory skin condition associated w/ papules & pustules involving the pilosebaceous units

PATHO: 4 main factors
- follicular hyperkeratinization
- increased sebum production
- Propionibacterium acne overgrowth
- inflammatory response

sx
Commonly seen in areas w/ increased sebaceous glands (face, back, chest, upper arms)

Comedones: small, noninflammatory bumps from clogged pores; surrounding erythema
*open (blackheads) – incomplete blockage
*closed (whiteheads) – complete blockage

Inflammatory: papules or pustules surrounded by inflammation
Nodular or cystic: often heals w/ scarring or hyperpigmentation

dx
Mild: <20 comedones, <15 inflammatory lesions, total <30

Moderate: 20-100 comedones, 15-50 inflammatory lesions, total 30-125

Severe: >100 comedones, >50 inflammatory lesions, >5 cysts, total >125

tx
Mild: topical retinoids (tretinoin, adapalene, tazarotene) + benzoyl peroxide (use at different time of day than retinoids); topical abx also used (erythromycin, clindamycin) *AVOID abx (topical & PO) as monotherapy

Moderate: PO abx + BPO &/or topical retinoids
*>8y: tetracycline, doxycycline, minocycline
*<8y: erythromycin, azithromycin, TMP-SMX
*hormones: OCPs, spironolactone
Severe (refractory nodular acne): PO isotretinoin

Question 2

Isotretinoin MOA

Answer 2

MOA: all 4 of the pathophysiological mechanisms of acne (most effective medication)

Indications: usually reserved for severe or refractory acne

ADRs
*dry skin & lips (MC), dry eyes
*highly teratogenic
*must obtain 2 (-) pregnancy tests prior to initiation
*pregnancy tests q monthly while on treatment
*must commit to 2 forms of contraception (used 1mo prior-1mo after D/C)
*↑ triglycerides & cholesterol
*arthralgias, myalgias, hepatitis, leukopenia, premature long bone closure
*photosensitivity, worsening of DM, HA, idiopathic intracranial HTN, fatigue, possibly psychiatric
*due to severe risk of teratogenesis, prescribers & patients must sign up for iPledge

Question 3

Androgenic Alopecia definition, sx, dx, tx

Answer 3

Genetically predetermined progressive loss of the terminal hairs on the scalp in a characteristic distribution (pattern)

MC type of hair loss in men & women; gradual in onset & usually occurs after puberty
M 20-40y, W >50y

PATHO:
*DHT is the key androgen; activation of the androgen receptor shortens the anagen (growth phase) in the normal hair growth cycle
*pathologic specimens show decreased anagen to telogen ratio

sx
Varying degrees of hair thinning & nonscarring hair loss
Males: begins as bitemporal thinning of the frontal scalp then involves the vertex
Females: thinning of the hair between the frontal & vertex of the scalp w/o affecting the frontal hairline

dx
Clinical
Dermoscopy: miniaturized hair & brown perihilar casts
BX: telogen & atrophic follicles
Trichogramma: ↑ telogen hairs
Hormones: testosterone, DHEA, prolactin
Treatable: thyroid (TSH), anemia (CBC), autoimmune (ANA)

tx
Topical minoxidil – 4-6mo trial before improvement
*MOA: vasodilator
*ADRs: pruritis & local irritation w/ flaking

Oral finasteride: 5-⍺-reductase type 2 inhibitor
*MOA: androgen inhibitor (inhibits conversions of testosterone to DHT)
*ADRs: ↓ libido, sexual or ejaculatory dysfunction, ↑ risk of high-grade prostate cancer, category X

Spironolactone: blocks DHT
Hair transplant

Question 4

Perioral Dermatitis definition, sx, dx, tx

Answer 4

MC seen in young adult women (20-45)

Risk Factors: hx of topical steroid use, fluorinated toothpaste

sx
Erythematous grouped papulopustules, which may become confluent into plaques w/ scales; may have satellite lesions
*classically spares the vermilion border

dx: clinical, redness around the mouth, clear borders

tx
Elimination of topical steroids & irritants
Topical:
- pimecrolimus
- metronidazole
- erythromycin
PO doxycycline if extensive or refractory

Question 5

Contact Dermatitis definition, sx, dx, tx

Answer 5

Inflammation of the dermis & epidermis from direct contact between a substance & the surface of the skin

Irritant (MC): non-immunologic rxn (immediate)
- chemicals, alcohols, creams

Allergic: type IV hypersensitivity rxn (delayed)
- nickel MC, poison ivy

sx
Acute: erythematous papules or vesicles (may be linear or geometric)
*localized pruritis, stinging, or burning

Chronic: lichenification, fissuring, & scales
*well-demarcated border

dx
Clinical
Patch testing may identify potential allergens

tx
Identification & avoidance of irritants
Topical steroids first line (triamcinolone)
PO steroids in severe or extensive reactions
- alt: topical tacrolimus or pimecrolimus

Question 6

Diaper Dermatitis definition, sx, dx, tx

Answer 6

Rash on buttocks region; common in infants 3wks-2yrs

Causes: wet, dark, friction, urine, feces, microorganisms

Secondary infections:
*satellite lesions 🡪 candidiasis
*impetigo (S. aureus)
*HSV (child sexual abuse)

dx
*fussiness
*crying w/ diaper change
*diarrhea
*shiny erythema w/ dull margins

*regular diaper dermatitis SPARES SKIN FOLDS
*Candidal diaper rash INVOLVES SKIN FOLDS

dx
Candida: KOH prep, fungal culture
Scabies: viral culture, mineral oil slide
S. aureus, group A strep: culture of skin lesions
*often have concurrent thrush

tx
*keep area dry to allow airflow
*barrier creams: zinc oxide, petroleum jelly
*candidiasis: nystatin, clotrimazole, econazole x2wks

*discuss proper diaper changes, disposable, avoid tight-fitting

Question 7

Atopic Dermatitis (Eczema) definition, sx, dx, tx

Answer 7

Rash due to defective skin barrier susceptible to drying, leading to pruritis & inflammation

Atopic Triad:
*eczema + allergic rhinitis + asthma

PATHO: disruption of the skin barrier & disordered immune response; onset MC <5yo; resolves/improves in >75% pts by adulthood

Triggers: heat, sweat, allergens, contact irritants

sx
*dry (xerosis), PRURITIC skin
*acute changes: erythema, vesicles, crusting
*chronic changes: lichenification, scaling, hyper/hypopigmentation

*infantile: erythematous, scaly lesions on cheeks, scalp, extensor surfaces; diaper area usually spared
*childhood: lichenified plaques in flexural areas
*adolescence: more localized & lichenified skin changes; may be predominantly on hands/feet

Nummular/Discoid Eczema: sharply defined coin-shaped lesions; dorsum of hands/feet, extensor surfaces

dx
Clinical
↑ IgE supports the dx

tx
Topical steroids first line q1-2x/d x7d for flares
*triamcinolone
Antihistamines for itching
Abx if secondary infection develops

Topical calcineurin inhibitors: second-line
*tacrolimus, pimecrolimus

Systemic: phototherapy (UVA, UVB), cyclosporine, azathioprine, mycophenolate, methotrexate

Lifestyle: avoid products w/ alcohol, fragrances, & astringents; pat skin dry, frequent use of bland lubricants (petroleum jelly, Vaseline, Aquaphor)

Question 8

Seborrheic Dermatitis definition, sx, dx, tx

Answer 8

PATHO:
*not fully understood, increased sebaceous gland activity + hypersensitivity reaction to Malassezia furfur
-more severe in pts w/ neuro dz (PD) & HIV
-MC in men
-worsen during fall/winter, stress

sx
Erythematous plaques w/ fine white scales & greasy appearance

Common in areas w/ high sebaceous gland secretion – scalp (dandruff), eyelids, beard, mustache, nasolabial folds, chest, groin

May be associated w/ burning & pruritis

dx: clinical

tx
Mild: topical first line
- selenium sulfide
- sodium sulfacetamide
- zinc pyrithione
- ketoconazole (shampoo or cream)
- low potency steroids

Severe or resistant: oral antifungals
- itraconazole, fluconazole, ketoconazole, terbinafine

Question 9

Burns common causes in infants, toddlers, school age, adolescents

Answer 9

Infants: bathing-related scalds, abuse
Toddlers: scalds by hot liquid spills
School-age: fire (playing w/ matches)
Adolescents: volatile agents, high-voltage electrical lines

Question 10

Burns rule of 9’s for children

Answer 10

Head: 18%
Front: 18%
Back: 18%
1 arm: 9%
1 leg: 14%

Question 11

Superficial (First Degree)

Answer 11

*mild inflammatory response confined to epidermis
*redness, DRY
*tenderness to palpation; blanches w/ pressure
*heals 3-6d (no scarring)

Question 12

Superficial Partial-Thickness (Second Degree)

Answer 12

*epidermis + superficial (papillary) dermis
*pink-red, weeping/MOIST; BLISTERING
*painful, blanches w/ pressure
*heals 7-21d (no scarring, +/- pigment changes)

Question 13

Deep Partial-Thickness (Second Degree)

Answer 13

*epidermis + deeper (reticular) dermis
*mottled color variation from cheesy white to red
*WET or WAXY; BLISTERING
*painful ONLY w/ pressure, does NOT blanch w/ pressure
*heals 3-9wks (+ hypertrophic scarring)

Question 14

Full-Thickness (Third Degree)

Answer 14

*epidermis + all of dermis + subQ tissue
*varies, waxy white to leathery gray to charred/black
*DRY, inelastic; no blistering
*lack of sensation; does NOT blanch w/ pressure
*requires surgery for healing

Question 15

Fourth Degree

Answer 15

*epidermis + dermis + subQ fat + fascia, muscle, bone
*black, CHARRED; dry, no blistering
*no sensation, does NOT blanch w/ pressure
*requires surgery for healing

Question 16

Burns dx and tx

Answer 16

DIAGNOSTICS:
BSA: superficial (first degree) NOT included
*anterior head 9%, posterior head 9%
*anterior torso 18%, posterior torso 18%
*anterior arm 4.5%, posterior arm 4.5%, total 9%
*anterior leg 7%, posterior leg 7%, total 14%
*genitalia/perineum 1%

Labs: ABG, CBC, CK, CMP, UA, carboxyhemoglobin

tx
*circumferential burns may require fasciotomy

Superficial & superficial partial thickness: wound care
*remove sloughing epidermis w/ gauze & sterile water
*do not rupture blisters
*topical abx (bacitracin) & wound dressing (xeroform)
*daily dressing changes, f/u in 2d

Analgesia: fentanyl, morphine
Td vaccine

Fluid Resuscitation: Parkland Formula, 3ml x TBSA% x wt (kg)
*50% given over first 8h, 50% given over next 16hr

Maintenance Fluids: 4-2-1 Rule
*4ml for first 10kg + 2ml for next 10kg + 1ml for each kg >20

Burn Center Admit Criteria:
*>10% BSA or ANY deep partial/full-thickness burns
*significant burns to hands, face, feet, genitalia/perineum
*electrical, chemical, or inhalational injury
*circumferential burns, underlying chronic condition, abuse

Question 17

Erythema Multiforme definition, sx, dx, tx

Answer 17

Type IV hypersensitivity reaction of the skin often following infections or medication exposure – MC in young adults 20-40yrs

Etiology:
Infections: HSV MCC; M. pneumoniae, VZV, EBV, CMV, coxsackie, parvovirus B19, M. tuberculosis, Salmonella, HIV
Medications: NSAIDs, sulfonamides, anticonvulsants, antibiotics

CLASSIC target lesions: THREE zones, well defined borders

sx
Target lesions – MC on extremities (hands/feet)
*dusky, violaceous macule or blister
*intermediate surrounding ring of pallor
*peripheral erythematous ring
NON-PRURITIC, blanches

NEGATIVE Nikolsky sign (no epidermal detachment)

Mucositis: typically mild & limited to one mucous membrane (usually oral); conjunctival/urogenital involvement rare

Minor: EM w/o or w/ only mild mucosal dz; NO systemic sxs
Major: EM w/ severe mucosal involvement + systemic sxs (fever, arthralgias)

dx
Clinical
Bx if dx not clear

tx
SELF-LIMITED!!
Symptomatic TX: bland emollients or topical abx applied to eroded areas, IVF for pts w/ mucositis & poor PO intake, antihistamines if pruritic
HSV: acyclovir
If ophthalmic involvement 🡪 REFERRAL

Question 18

SJS & TEN definition, sx, dx, tx

Answer 18

Rare hypersensitivity reactions affecting the skin & mucosal membranes

Etiology: predominantly drug-related (penicillin, sulfonamides, allopurinol, NSAIDs, anticonvulsants)
*other: infections (M. pneumoniae, influenza)

SJS: <10% BSA
SJS/TEN Overlap: 10-30% BSA
TEN: >30% BSA

ATYPICAL target lesions: TWO zones or poorly defined border

*Generally develops within 2mo of drug initiation, & often within first 1-4wks

sx
Prodrome: fever, malaise, pharyngitis, eye pain
Cutaneous: typically begin on torso & face; rapidly generalizes

SJS: atypical targetoid lesions, often violaceous &/or blistered; lesions may coalesce, particularly on face & torso

TEN: tender, erythematous patches & plaques that develop large bullae that coalesce & rapidly slough, leaving large, denuded areas of skin

(+) Nikolsky sign: applied lateral pressure to blister causes extension of separation from dermis

Mucositis: oropharyngeal, conjunctival, urethral, genital, perirectal; often causes pain, poor PO intake, dehydration
Ocular manifestations: conjunctivitis, eyelid edema, blepharitis, corneal erosions, symblepharon, corneal scarring

dx
Clinical
Bx: full thickness skin necrosis
Consider: bacterial cultures, M. pneumoniae PCR

SJS: <10, most common in children, mainly dt drug reactions, >2 mucous sites, URI prodrome
TEN: >30%, most commonly in elderly, abrupt onset, mucous membrane involvement, positive Nikolsky

tx
PROMP DC OF ALL POSSIBLE INCITING MEDS!!!

Supportive: pain management, nutritional support, maintain normal body temperature, maintain hydration & electrolyte balance
*hypo-Na/K/phos common

Wound care: leave bullae intact, avoid aggressive debridement, petroleum gauze, topical antibiotics, minimize pressure, frequent application of bland emollients/lubricating ointments to involved mucosa, +/- PO disinfectant rinse (chlorhexidine)

IVIG: may be effective at arresting progression

Question 19

Cutaneous Drug Reactions defintion and types

Answer 19

Medication-induced changes in the skin & mucous membranes – most are hypersensitivity reactions
Most cutaneous drug reactions are self-limited if the offending drug is D/C
Triggers: antigen from foods, insect bites, drugs, environmental, exercise-induced, & infections

Type I: IgE mediated – e.g., urticaria, angioedema; immediate
Type II: cytotoxic, antibody-mediated (drugs + cytotoxic antibodies cause cell lysis)
Type III: immune antibody-antigen complex e.g., drug-mediated vasculitis & serum sickness
Type IV: delayed (cell mediated) – morbilliform reaction e.g., erythema multiforme
Non-immunologic: cutaneous drug reactions d/t genetic incapability to detoxify certain meds (anticonvulsants, sulfonamides)

Question 20

Exanthematous Drug Eruption definition, sx, dx, tx

Answer 20

Morbilliform or maculopapular drug eruption characterized by macules or small papules after the initiation of drug treatment

MC occurs 5-14d after the initiation of the offending med or within 1-2d in previously sensitized individuals

PATHO: type IV (delayed) hypersensitivity
*MC drugs: antibiotics (aminopenicillins, sulfonamides), anticonvulsants (carbamazepine)

sx
Latency (not previously sensitized): cutaneous eruption typically occurs within 7-10d after starting tx; for short courses of tx (e.g., antibiotics), the eruption may appear 2-4d AFTER stopping tx

Cutaneous features: erythematous macules &/or papules; morbilliform (measles like), rubelliform (rubella like); predominantly involves trunk/proximal extremities
*mild – acral sites often spared
*severe – can involve face, palms/soles

Systemic sxs (mild): pruritis, low-grade fever

dx
CLINICAL DX
Labs: slightly elevated acute phase reactants, mild eosinophilia

tx
Prompt withdrawal of the offending med
Symptomatic: oral antihistamines (H1 blockers)
- second gen: cetirizine, loratadine, fexofenadine
- first gen: diphenhydramine, hydroxyzine, chlorpheniramine

Severe: short course of PO steroids

Question 21

Angioedema definition, sx, dx, tx

Answer 21

Angioedema
Self-limited, localized subcutaneous (or submucosal) swelling resulting from extravasation of fluid into the interstitium

Affects the mucosal tissues of the face, lips, tongue, larynx, hands, feet, & genitalia

Onset in min-hours w/ spontaneous resolution in hours-few days

sx
Mast-cell (histamine) mediated (e.g., allergic rxns)
*angioedema that may be accompanied w/ other allergic rxn sxs (urticaria, flushing, pruritis, bronchospasm, stridor, throat tightness, hypotension)

Bradykinin-mediated (e.g., ACEI-induced or hereditary – d/t C1 esterase inhibitor deficiency
*angioedema w/o allergic reaction sxs

dx
If there is no information to suggest an external cause & the patient has isolated angioedema (w/o pruritis or urticaria), then C4 levels & a C1 inhibitor antigenic level should be obtained

tx
Immediate: immediate assessment & ongoing airway protection; epi if severe
Mast-cell mediated: epi (if severe), steroids, antihistamines
Bradykinin-mediated: C1 inhibitor concentrate, ecallantide, icatibant

Question 22

Urticaria (Hives) definition, sx, dx, tx

Answer 22

Edema of the superficial layers of the skin due histamine-related increased vascular permeability

Type I (IgE) immediate hypersensitivity reaction

PATHO: release of vasodilators (histamine, bradykinin, kallikrein, PGs) form mast cells & basophils of the skin

sx
Triggers: foods, meds, heat or cold, stress, insect bites, environmental, & infection
- chronic (>6wks)

Sudden onset of circumscribed hives or wheals (blanchable, raised, erythematous areas on the skin or mucous membranes) that may coalesce
*intense pruritis
*usually transient (often disappearing within 24hrs)

tx
Antihistamines (H1 blockers) initial
- second gen: cetirizine, loratadine, fexofenadine
- first gen: diphenhydramine, hydroxyzine, chlorpheniramine

H2 blockers (ranitidine) may be added if no response to H1 blockers

Severe, recurrent, persistent: steroids

Question 23

Drug Reaction w/ Eosinophilia & Systemic Symptoms (DRESS)/Drug-Induced Hypersensitivity Syndrome (DIHS) definition, sx, dx, tx

Answer 23

Definition: distinct & potentially life-threatening severe ADR characterized by a morbilliform cutaneous eruption w/ fever, LAD, hematologic abnormalities, & multiorgan manifestations

PATHO: appears to be mediated by activation of CD4+ & CD8+ T lymphocytes; most often occurs 2-6wks after medication initiation

Etiology: SAPAN: MCC are anticonvulsants (phenobarbital, carbamazepine phenytoin, lamotrigine), minocycline, sulfa abx

sx
Prodrome: fever, pharyngitis, malaise 2-3d before rash onset
Skin: morbilliform exanthem w/ accentuation on face, upper trunk, proximal extremities; may progress to erythroderma; pruritis common
*desquamation develops days-weeks after initial eruption; can last several weeks

Other manifestations: facial edema (esp. periorbital), LAD, mucosal involvement (cheilitis, pharyngeal erythema)

Organ system involvement: hepatitis, tubulointerstitial nephritis, pulmonary sxs (SOB, tachypnea, cough)
*rash/other abnormalities resolve 1-2mo after med DC

Autoimmune complications: Graves, DM1, AIHA

DX Criteria: acute onset exanthema w/ fever, suspicion of drug reaction, hospitalization, LAD, involvement of ≥1 internal organ, & hematologic abnormalities (lymphopenia, lymphocytosis, atypical lymphocytosis, eosinophilia >10%, thrombocytopenia)

CBC: can show lymphocytosis, atypical lymphocytosis, eosinophilia, thrombocytopenia

LFTs: ↑ ALT, alk phos; CMP: ↑ creatinine; ↑ LDH

UA: proteinuria, eosinophilic sediment
Blood PCR: HHV-6, HHV-7, EBV, CMV

Hepatitis panel: HAV IgM Ab, HBsAg, HBcAb (IgM), HCV viral RNA
TFTs: @baseline, again @6wks

tx
DERM CONSULT!

*identify & DC causative medication
*fluid replacement, electrolyte correction

Mild, predominantly cutaneous: topical corticosteroids; antihistamines for pruritis

Significant systemic involvement:
*systemic steroids; prednisone, methylprednisolone
*IVIG for no response to steroids; plasmapheresis, immunosuppressive drugs are other options

Question 24

Rubeola (Measles) – 1st Disease definition, sx, dx, tx

Answer 24

Etiology: measles virus, paramyxovirus family

Transmission: respiratory droplets, contact w/ contaminated surface
Incubation: 6-21d

sx
Prodrome: high fever + 3Cs (cough, coryza, conjunctivitis); usually lasts 3d

Koplik spots: small red spots w/ white centers on oral mucosa
*rash follows by 1-2d

Rash: maculopapular rash; cephalocaudal progression (head downwards)
*spares palms/soles; fades ~4d; left w/ persistent cough for 10-14d

dx
Clinical
Measle-specific IgM antibodies, PCR
Vaccine: MMR @12-15mo, 2nd dose @4-6y

tx
Supportive: acetaminophen, ibuprofen, oral hydration
*vitamin A for young/severely malnourished children; boosts immune response; ↓ risk of complications & death

Complications: severe diarrhea MC, pneumonia (MCC of deaths), subacute sclerosing panencephalitis (7-10y later)
*can suppress immune system for 6wks 🡪 otitis media, bacterial pneumonia

Question 25

Scarlet Fever – 2nd Disease definition, sx, dx, tx

Answer 25

Etiology: group A strep

PATHO: type IV (delayed) hypersensitivity reaction to a pyrogenic strain (erythrogenic toxin A, B, C)

sx
Prodrome: fever, chills, pharyngitis

Rash: diffuse erythema that blanches w/ pressure + multiple small papular elevations w/ sandpaper texture
*axillae/groin 🡪 trunk/extremities (spares palms/soles)

Flushed face w/ circumoral pallor & strawberry tongue

Pastia’s Lines: linear petechial lesions seen at pressure points, axillary, antecubital, abdominal, or inguinal areas

dx
Clinical
Testing for GABHS

tx
Penicillin G or VK first line
- amoxicillin
- macrolides if PCN allergy
- clindamycin, cephalosporins

Question 26

Rubella – 3rd Disease (German Measles)
“3d measles” definition, sx, dx, tx

Answer 26

Etiology: rubella virus, togavirus family
Transmission: respiratory droplets
Incubation: 14d

sx
Prodrome: flu-like sxs (mild fever), arthralgias, postauricular LAD

Rash: erythematous, maculopapular rash; cephalocaudal spread (face downwards)
*spares palms/soles; disappears within 3d aka “3d measles”
*spreads much more rapidly than measles, does not darken/coalesce

Forchheimer spots: pinpoint red macules & petechiae on soft palate & uvula

dx
Clinical
Rubella-specific IgM Ab via EIA

tx
Supportive: acetaminophen, ibuprofen, oral hydration
*immunoglobulin in exposed individuals
Vaccine: MMR @12-15mo, 2nd dose @4-6y
Complications: teratogenic in 1st TM
*deafness, cataracts, congenital heart defects (PDA)

Question 27

Erythema Infectiosum – 5th Disease definition, sx, dx, tx

Answer 27

Etiology: parvovirus B19 – infects & destroys reticulocytes, leading to a ↓ or transient halt in erythropoiesis

Transmission: respiratory droplets
Incubation: 4-14d; asymptomatic

sx
Prodrome: flu-like sxs (mild fever, HA, malaise); *rash follows by a few days

Rash: “slapped cheek” rash; lacy reticular rash on extremities; spares palms/soles; resolves in 2-3wks
*arthritis or arthralgias in older children/adults

dx
Clinical
Serologies: parvovirus B19-specific IgM antibodies

tx
Supportive: acetaminophen, NSAIDs
Complications: hydrops fetalis in pregnancy, aplastic crisis in pts w/ sickle cell

Question 28

Roseola Infantum – 6th Disease (Exanthema Subitum) definition, sx, dx, tx

Answer 28

Etiology: MC caused by HHV-6; less commonly HHV-7
Transmission: respiratory droplets, saliva
Incubation: 10d

MC in children 6mo-2y

sx
Prodrome: 3d of high fever – child appears well during febrile phase; can reach >104F

Rash: pink maculopapular blanchable rash
*starts on trunk 🡪 face (only viral exanthem that starts on the trunk)

Fever THEN RASH

dx
Clinical
Viral culture/PCR for confirmation
IgG antibodies against HHV-6/7

tx
Supportive: rest, fluids, antipyretics (acetaminophen)
Immunocompromised: antivirals (ganciclovir)
Complications: febrile seizures

Question 29

Hand, Foot, & Mouth Disease definition, sx, dx, tx

Answer 29

Etiology: coxsackie virus A
Transmission: person-person, respiratory droplets, feces, direct contact w/ contaminated surface

MC in children <5yrs; MC in summer/early fall

sx
Prodrome: flu-like sxs, oral pain *rash follows within few days

Rash: painful vesicles & ulcers in mouth 🡪 vesicles on palms/soles
*usually clears within 10d

dx
Clinical – viral culture/PCR of throat swab or stool sample
Coxsackie-specific immunoglobulin A

tx
Supportive: acetaminophen, ibuprofen, hydration, topical lidocaine; usually resolves in 1wk
Complications: aseptic meningitis, Guillain-Barre syndrome

Question 30

Herpangina definition, sx, dx, tx

Answer 30

Etiology: coxsackie virus (esp. type A)

MC in children 3-10yrs; MC in summer/early fall

sx
Sudden onset high fever

Stomatitis: small yellow white papulovesicular lesions on posterior pharynx (soft palate, uvula, tonsils) that ulcerate before healing
*anorexia due to pain common
*pharyngitis, odynophagia
*NO SORES ON HANDS/FEET

In older children: +/- malaise, HA, N/V, neck stiffness, back stiffness

dx
Clinical
Coxsackie-specific immunoglobulin A; viral culture

tx
Supportive: acetaminophen, ibuprofen, hydration
Complications: aseptic meningitis, Guillain-Barre syndrome

Question 31

Mumps definition, sx, dx, tx

Answer 31

Etiology: paramyxovirus
Transmission: respiratory droplets, saliva, household fomites
Incubation: 12-14d

sx
Prodrome: low-grade fever, fatigue, myalgia, malaise, HA, earache
Parotitis: parotid gland pain & swelling; usually bilateral

PE: parotid gland swelling & tenderness

dx
Clinical, serologies
↑ amylase, leukopenia w/ a relative lymphocytosis

tx
Supportive: acetaminophen, ibuprofen, analgesics
Complications: epididymo-orchitis MC

Question 32

Varicella Zoster Virus (HHV-3) definition, sx, dx, tx

Answer 32

VZV causes 2 clinically distinct diseases:
*Primary: varicella (chickenpox)
*Reactivation: herpes zoster (shingles)

Transmission: aerosolized droplets, direct contact w/ vesicular fluid
Incubation: 14-21d; asymptomatic

Travels retrograde to trigeminal ganglion & dorsal root ganglia where it can remain dormant in a latent state for many years; later, if immune system weakens (aging, stress, immunosuppressive therapy), virus can be reactivated & travel anterograde through sensory nerve to skin (herpes zoster/shingles)

*HHV-3 virus

sx
Varicella (chickenpox): “dew drops on a rose petal”
Prodrome: fever, malaise, anorexia, pharyngitis; rash appears 24h later
Rash: *appears in successive crops over several days
*starts as macules, rapidly become papules, then vesicles; can develop pustular component followed by formation of crusted papules; crusts fall off within 1-2wks; leave temporary area of hypopigmentation
*lesions in different stages of development, PRURITIC!!!

Herpes zoster (shingles):
Prodrome: pain, itching, or tingling in area where rash will develop
Rash: single stripe of vesicles (single dermatome); don’t cross midline
*usually resolves within 1mo, but pain can last >90d 🡪 postherpetic neuralgia

Zoster Ophthalmicus: involves ophthalmic division of trigeminal nerve; 5
*eye pain, redness, swelling + fever + painful vesicular rash
Zoster Oticus (Ramsay-Hunt Syndrome): involves facial nerve (8)
*otalgia; lesions on ear, auditory canal, & TM; facial palsy, hearing loss

dx
Clinical
PCR: viral DNA; confirmatory
Blood tests: IgM antibodies

Tzanck smear:
*multinucleated giant cells

Zoster Ophthalmicus:
*dendritic lesions on slit lamp if keratoconjunctivitis is present

tx
Varicella (chickenpox): resolves in 1wk; develop immunity
*healthy children <12yo: supportive (ASPIRIN 🡪 REYE)
*≥13y & unvaccinated, immunocompromised: antivirals
PO acyclovir, valacyclovir, famciclovir
*varicella-zoster immune globulin (VZIG)

Herpes zoster (shingles): rash usually resolves in 1mo
*acyclovir, valacyclovir, famciclovir within 72h to prevent postherpetic neuralgia
Zoster Ophthalmicus: PO antivirals, can add acyclovir ophthalmic
Ramsay-Hunt: PO acyclovir, corticosteroids
Postherpetic Neuralgia: gabapentin, TCAs, topical lidocaine gel, capsaicin

Vaccines: varicella @12-15mo, second dose 4-6y; recombinant zoster vaccine (RZV) in pts >50y, 2 doses 2-6mo apart

Question 33

Impetigo definition, sx, dx, tx

Answer 33

Highly contagious superficial vesicopustular skin infection

MC bacterial skin infection in children (highest incidence 2-6yrs)

Risk Factors: poor personal hygiene, poverty, crowding, warm & humid weather, skin trauma

Complications:
*cellulitis MC (10%)
*acute glomerulonephritis

*does not lead to rheumatic fever

sx
Non-bullous (MC): vesicles, pustules; weeping, “honey-colored crust”
*occurs at sites of superficial skin trauma (insect bites)
*around nose/mouth, associated w/ regional LAD
*MCC: S. aureus, GABHS

Bullous: vesicles, then bullae, varnish-like crust
*fever, diarrhea
*MCC: S. aureus
*rare (seen in newborns or younger children)

Ecthyma: ulcerative pyoderma caused by group A strep (heals w/ scarring); not common

dx
Clinical
Gram stain & wound culture

tx
Mild: topical mupirocin TID x10d
- bacitracin
- retapamulin
- wash area w/ soap/water
- good skin hygiene

Extensive disease or systemic sxs: systemic abx
- cephalexin or erythromycin x1wk
- dicloxacillin
- macrolides

MRSA: doxycycline; Sick + MRSA: vancomycin

Question 34

Scabies definition, sx, dx, tx

Answer 34

A highly contagious skin infection due to the mite Sarcoptes scabiei

PATHO: female mites burrow into the skin to lay eggs, feed, & defecate (scybala are the fecal particles that precipitate a hypersensitivity reaction in the skin)

sx
Intense pruritis, esp. at night
Infected pts may remain w/o sxs for up to 4-6wks

PE:
*multiple, small erythematous papules, excoriations
*linear burrows – commonly found in the intertriginous zones, including the scalp & web spaces between the fingers & toes; usually spares neck & face
*red itchy pruritic papules or nodules on the scrotum, glans, penile shaft, or body folds

dx
Clinical
Skin scrapings: mites, eggs, feces seen w/ magnification

tx
Topical permethrin DOC
Lindane
- do NOT use after showers (causes seizures d/t increased absorption through open pores
- CI: teratogenic, not usually used in breastfeeding & children <2yrs

Ivermectin if extensive
All clothing, bedding, etc. should be placed in a plastic bag at least 72hrs then washed & dried using heat

Question 35

Pediculosis Pubis “pubic lice” definition, sx, dx, tx

Answer 35

Transmission: usually sexually transmitted (esp. in teenagers & young adults)

sx
Pruritis of the involved area
Nits may be seen

dx
Clinical (visual of lice or nits)
Microscopic exam of hair shaft

tx
Topical permethrin or pyrethrins first line

Question 36

Pediculosis Capitis “head lice” definition, sx, dx, tx

Answer 36

Transmission: person to person; fomites (hats, headsets, clothing, bedding)

Girls > boys; less common in AA
Outbreaks commonly affect children 3-12yrs, warmer & humid weather

sx
Intense itching (esp. occipital area); papular urticaria near lice bites

PE:
*visualization of crawling nymphs or adult lice; presence of nits alone does NOT confirm infection
*nits: white, oval-shaped egg capsules at the base of the hair shafts

tx
Topical permethrin – fine tooth comb to remove nits
- alt: malathion
- benzyl alcohol, Spinosad, topical ivermectin

Lindane
- ADRs: neurotoxic (HA, seizures)
Oral ivermectin in refractory cases

Question 37

Pediculosis Croppers “body lice” definition, sx, dx, tx

Answer 37

Transmission: usually sexually transmitted; strongly related to poor body hygiene (homeless, prisons, crowded, etc.)

PATHO: do not live on the skin – live & lay their eggs in seams of clothing or bedding & move to the skin only to feed

Disease transmission: body lice can be a vector for diseases to humans, such as relapsing fever, epidemic typhus, & trench fever

sx: Pruritis & excoriations

dx: Clinical – identification in clothing, esp. the seams

tx
Hygiene improvement first line
Permethrin 5% cream

Question 38

Lichen Planus definition, sx, dx, tx

Answer 38

Acute or chronic inflammatory dermatitis (cell-mediated immune response)

Increased incidence: hepatitis C, drug reactions, graft vs. host, malignant lymphoma
MC in adults

sx
Pruritic rash MC on the extremities, esp. the volar surfaces of the wrist & the ankles
*may involve the mouth, scalp, genitals, nails, & mucous membranes
PE:
*6 Ps: purple, polygonal, planar, pruritic, papules or plaques w/ fine scales & irregular borders that may have Wickham striae (fine white lines on the skin lesions or on the oral mucosa)
Koebner’s phenomenon: new lesions at sites of trauma (also seen in psoriasis)
*nail dystrophy; may cause scarring alopecia

dx
Clinical
Bx & immunofluorescence is confirmatory – saw-tooth lymphocyte infiltrate at the dermal epidermal junction

tx
Topical steroids first line w/ occlusive dressings
- antihistamines for pruritis

Second line: PO or intralesional steroids, topical tretinoin or photosensitizing psoralen + ultraviolet light therapy (generalized eruptions)
Usually resolves spontaneously in 8-12mo

Question 39

Pityriasis Rosea definition, sx, dx, tx

Answer 39

Etiology: uncertain – may be associated w/ viral infections (HHV-6 or 7)

Primarily seen in older children & young adults (rare >35yrs); increased incidence in spring/fall

sx
Herald patch: solitary salmon-colored macule on the trunk, 2-6mm

1-2wks later general exanthem: smaller, very pruritic 1cm round or oval salmon-colored papules w/ white circular (collarette) scaling in a Christmas tree pattern (oriented along skin cleavage lines)
*confined to trunk & proximal extremities (face, palms, soles usually spared)

dx
Clinical
Young adults 🡪 RPR to r/o syphilis

tx
No management needed for most – education, reassurance, tx of pruritis (resolves spontaneously in 6-12wks)
- PO antihistamine
- topical steroids

Lotions or emollients for scaling

Question 40

Staphylococcal Scalded Skin Syndrome (SSSS) definition, sx, dx, tx

Answer 40

Superficial skin blistering condition due to dissemination of S. aureus exfoliative toxins (esp. S. aureus strains 71 & 55)

PATHO:
*toxins cleave desmoglein-1, resulting in the formation of flaccid, fragile bullae

MC in infants (3-7d) or children <5yrs

sx
Erythema phase:
*fever, irritability, skin tenderness 🡪 cutaneous blanching erythema (often begins @ mouth); erythema is worse in flexor areas & around orifices

Bullae phase:
*sterile, flaccid blisters occur about 1-2d after the erythema, esp. in the areas of mechanical stress (flexural areas, buttocks, hands, feet)
*(+) Nikolsky sign

Desquamative phase:
*skin that easily rupture, leaving moist, denuded skin before healing

Conjunctivitis may be seen but mucous membranes not involved

*Perioral, periocular, and perinasal erythema and crusting are characteristic

dx
Clinical
Cultures from blood or nasopharynx
Skin bx: splitting of the lower stratum granulosum layer

tx
Abx:
*nafcillin, oxacillin
*MRSA 🡪 vancomycin

Supportive care:
*maintain the skin clear & moist
*emollients to improve barrier function
*fluid & electrolyte replacement

STEROIDS CONTRAINDICATED

Question 41

Dermatophytosis definition, types, RF

Answer 41

Fungal skin infections: trichophyton, microsporum, Epidermophyton
Infects keratinized tissues in the stratum corneum of the skin, hair, & nails by ingesting keratin

Risk Factors: ↑ skin moisture (e.g., occlusive gear), immunodeficiency (HIV, DM), peripheral vascular disease

Question 42

Tinea Capitis “Ring Worm” definition, sx, dx, tx

Answer 42

Superficial fungal infection of the scalp
Etiologies: 90% caused by trichophyton
Risk Factors: poor hygiene, direct contact, preadolescents, MC in AA

sx
4 presentations:
Patches of alopecia w/ black dots
Scaly patches w/ alopecia
Kerion: severe manifestation characterized by an inflammatory plaque w/ pustules & thick crusting; often painful
Favus: less common – cup-like shaped yellow crusts composed of dried scalp secretions, fungi, skin cells, & dead inflammatory cells

dx
Clinical
KOH prep: fungal element inside or surrounding the hair

Wood’s lamp:
- trichophyton: no fluorescence
- microsporum: fluorescence

Culture: definitive

tx
PO griseofulvin – first line; 6-12wks
- ADRs: hepatitis, GI HA, disulfiram reaction
- better absorbed w/ fatty food (peanut butter)

2nd line: PO terbinafine

Lifestyle: use of antifungal by all house members, avoid sharing hats, clippers, & combs

Question 43

Tinea Barbae sx, tx

Answer 43

Papules, pustules, & hair follicles

tx
Requires PO antifungal: griseofulvin, terbinafine

Question 44

Tinea Pedis “Athletes Foot” definition, sx, dx, tx

Answer 44

MC dermatophyte infection
Transmission: direct contact (e.g., walking barefoot in gyms or swimming pool areas)
MC in adolescents & young men

sx
Interdigital (MC): pruritis, erythematous erosions or scales between the toes

Hyperkeratotic: diffuse hyperkeratotic rash involving the soles, lateral & medial surfaces of the feet w/ a “moccasin” distributive pattern

Vesiculobullous: pruritic vesicular or bullous eruption w/ underlying erythema, esp. involving the medial surfaces of the foot (may be painful)

dx
Clinical
KOH prep: segmented hyphae
Wood’s lamp:
- trichophyton: no fluorescence
- microsporum: fluorescence
Culture: definitive

tx
Topical antifungals first line (4wks)
- butenafine, tolnaftate, ciclopirox, azoles
- terbinafine 1% cream x1wk
- Burrow’s solution added for hyperkeratotic

If topical is ineffective: PO terbinafine, fluconazole, itraconazole

Clean shoes w/ antifungal spray, keep cool/dry

Question 45

Tinea Cruris “Jock itch” definition, sx, dx, tx

Answer 45

Superficial fungal infections of the groin or inner thighs
Etiologies: fungi of the trichophyton (T. rubrum MC)

Risk Factors: males, copious sweating (close contact sports, wearing tight clothing), immunocompromised
- tinea pedis may be the source of infection

sx
Pruritis hallmark

Annular patches or plaques, diffuse erythema to the inner thighs or groin w/ sharply demarcated raised border that may have tiny vesicles
*often spares the scrotum & the mucosa

dx
Clinical
KOH prep: segmented hyphae
Fungal cultures: definitive

tx
Topical antifungals first line
- clotrimazole, butenafine, terbinafine
- desiccant powders in the inguinal area w/ the avoidance of tight-fitting clothing & noncotton underwear

PO antifungals if topical ineffective or extensive
- terbinafine
- griseofulvin

Question 46

Tinea Corporis “ringworm” definition, sx, dx, tx

Answer 46

Superficial fungal infection of the body (trunk, legs, arms, or neck)
- does not include the feet, hands, groin, nails, or the scalp
Etiologies: fungi of the trichophyton & microsporum genera (T. rubrum MC)

Transmission:
*direct contact – common in preadolescents
*infection from other animals
*infection from another part of the body

sx
Single or multiple pruritic, erythematous, scaly, circular or oval plaques or patches w/ central clearing & well-defined raised borders that spread outwardly
- may have pustules

dx
KOH prep: segmented hyphae
Culture: definitive

tx
Topical antifungals first line; 1-3wks
- azoles: clotrimazole, ketoconazole
- butenafine
- terbinafine
- naftine
- ciclopirox
- tolnaftate

PO antifungals if topical ineffective or extensive
- itraconazole
- terbinafine

Question 47

Pityriasis (Tinea) Versicolor definition, sx, dx, tx

Answer 47

Fungal skin infection due to overgrowth of the yeast Malassezia furfur
MC in adolescents & young adults

Risk Factors: hot & humid weather, excessive sweating, oily skin

sx
Hyper or hypopigmented, well-demarcated round or oval macules w/ fine scaling – often coalesce into patches MC on the upper trunk & proximal extremities
*the involved skin fails to tan w/ sun exposure

dx
KOH prep: hyphae & spores (“spaghetti & meatballs” appearance)

Wood’s lamp: yellow-green fluorescence (enhanced color variation seen w/ versicolor)

tx
Topical: first line
- selenium sulfide
- sodium sulfacetamide
- zinc pyrithione
- azoles

Systemic therapy: itraconazole, fluconazole
- in adults if widespread or failed topical therapy

Question 48

Verrucae definition, sx, dx, tx

Answer 48

Warts: all are caused by HPV; most resolve w/o tx over 2yrs

sx
Verruca Vulgaris (common warts)
*skin-colored papillomatous papules

Verruca Plana (flat warts)
*hands, face, arms, legs

Verrucae Plantaris (plantar warts)
*bottom of the foot; rough surface
*dark spot (thrombosed capillaries)

Epidermodysplasia Verruciformis
*a rare, lifelong hereditary disorder characterized by chronic infection w/ HPV

tx
Most resolve w/o tx over 2yrs
Cryotherapy – liquid nitrogen
Self-administered topical therapy:
*salicylic acid

Question 49

Psoriasis definition, sx, dx, tx

Answer 49

Immune-mediated multisystemic disease w/ a genetic predisposition

PATHO:
*keratin hyperplasia & proliferating cells in the stratum basale + stratum spinosum due to T cell activation & cytokine release
*this causes greater epidermal thickness & accelerated epidermis turnover

sx
Plaque (MC): raised, well-demarcated, pink-red plaques or papules w/ thick silvery white scales
*MC on the extensor surfaces of the elbows, knees, scalp, & nape of the neck; usually pruritic

Auspitz sign: punctate bleeding w/ removal of plaque or scale (nonspecific)

Koebner’s phenomenon: new isomorphic (similar) lesions at the sites of trauma

Nail involvement: pitting; yellow-brown discoloration under the nail (oil spot); separation of nail from nail bed (onycholysis)

Other variants:
Guttate: small, erythematous “tear drop” papules w/ fine scales, discrete lesions & confluent plaques; spares the palms & soles – often appears after strep pharyngitis

Inverse: erythematous (lacks scale); MC seen in body folds

Pustular: deep, yellow pustules that coalesce to form large areas of pus; fever, leukocytosis may be seen

Erythroderma: generalized erythematous rash involving most of the skin (worse type)

tx
Mild-moderate:
- topical steroids first line
- vitamin D analogs (calcipotriene)

Moderate-severe:
- phototherapy: UVB, PUVA (oral psoralen followed by ultraviolet A)

Severe:
- systemic tx: cyclosporine, retinoids (acitretin), biologic agents (TNF inhibitors – etanercept, adalimumab, infliximab)
- methotrexate usually last resort

Question 50

Erythema Toxicum Neonatorum definition, sx, dx, tx

Answer 50

*Occurs in approximately 20% of neonates in the first 72hrs of life
*May be present at birth, but usually appear within 24-48hrs
*Occurs more frequently in neonates w/ higher birthweight & greater gestational age

sx
*multiple erythematous macules & papules that rapidly progress to pustules on an erythematous base
*trunk & proximal extremities, spares palms/soles

dx
Clinical
Wright-stain smear 🡪 eosinophils *not necessary

no tx, resolves spontaneously in 5-7d

Question 51

Transient Neonatal Pustular Melanosis definition, sx, dx, tx

Answer 51

*mostly affects full-term Black infants

sx
Consists of 3 types of lesions:
(1) Small pustules on a non-erythematous base *usually present at birth
(2) Erythematous to hyperpigmented macules w/ a surrounding collarette of scale; develop as pustules rupture & may persist for wks-mos
(3) Hyperpigmented macules that gradually fade over several weeks to months

dx
Clinical
Wright-stain smear 🡪 neutrophils, rarely eosinophils *not necessary

no tx necessary

Question 52

Milia definition, sx, dx, tx

Answer 52

PATHO: caused by retention of keratin & sebaceous material in the pilosebaceous follicles

sx: white papules frequently found on nose & cheeks

dx: clinical

tx: resolve in the first few months of life

Question 53

Miliaria definition, sx dx, tx

Answer 53

Miliaria Crystallina: results from superficial blockage of the sweat duct

Miliaria Rubra (“heat rash”): results from blockage of the duct, usually within the epidermis

sx
Miliaria Crystallina: superficial, clear 1-2mm vesicles that resemble water droplets; no surrounding erythema
*MC involve head, neck, & upper trunk

Miliaria Rubra: erythematous 2-4mm papules
*MC in the skin folds of the neck, axilla, or groin

dx: clinical

tx
*cool environment, breathable clothing, gentle exfoliation w/ a rough cloth