Derm

Question 1

Burns: 1st, 2nd, 3rd and 4th degree

Answer 1

*Thermal: scalding, contact w/ hot surface, fires ▪︎Complications: bacterial superinfection, sepsis, respiratory damage, multiorgan failure
*Non-Thermal: radiation, chemical burns, electrical burns

Superficial (1st degree)
▪︎epidermis ▪︎“sunburn” ⇢ dry, red
▪︎painful
▪︎3-6d ▪︎ no blisters ▪︎ no scarring

Superficial partial thickness (second degree)
▪︎epidermis + superficial (papillary) dermis
▪︎Moist, red, weeping
⊕ w/ pressure
▪︎painful to temp.,
▪︎7-21d ▪︎⊕blisters air, & touch
▪︎⊖scarring, +/- pigment Δ

Deep partial thickness (2nd degree)
▪︎epidermis + deeper (reticular) dermis
▪︎mottled, cheesy white to red
⊖ or sluggish
▪︎painful to pressure
▪︎2-9wks w/o grafting
▪︎damage hair follicles & glandular tissue
▪︎wet or waxy dry only ▪︎⊕hypertrophic scarring ▪︎⊕blisters (easily unroof)

Full thickness (3rd degree)
▪︎epidermis + dermis + SQ tissue ▪︎waxy white to leather gray ▪︎deep pressure only
▪︎healing w/o surgery not
(3rd degree) to charred & black possible ▪︎dry & inelastic, ⊘blisters ▪︎⊕severe scarring, contractures

Deeper injury (4th degree) ▪︎epidermis + dermis + SQ + deep ▪︎black, charred, dry, dull ▪︎minimal perception
▪︎life & limb threatening
structures (muscles, fat, fascia, bones)
▪︎⊘blisters of deep pressure

Question 2

Criteria for Minor Burns

Answer 2

Criteria for Minor Burns: *pts meeting ALL criteria may be treated outpatient Burn Center Referral Criteria:
▪︎partial-thickness burns <10% TBSA in patients 10-50yo ▪︎partial-thickness burns >10% TBSA
▪︎partial-thickness burns <5% TBSA in patients <10yo or >50yo ▪︎third-degree burns in any age group
▪︎full-thickness burns <2% TBSA in any patient w/o other injury ▪︎burns of face, hands, feet, genitalia, perineum, or major joint
▪︎isolated injury (i.e., no suspicion of inhalation or high-voltage injury) ▪︎electrical burns (including lightning)
▪︎does not involve face, hands, feet, or perineum ▪︎chemical burns
▪︎does not cross major joints ▪︎inhalation injury
▪︎is not circumferential ▪︎burns in pts w/ medical conditions that could complicate
management, prolong recovery, or affect mortality

Question 3

Rule of 9s

Answer 3

Estimating %TBSA (adults):
Rule of 9s ⇢ superficial (1st degree) NOT included Palmar Method ⇢ uses PATIENT’S palm
▪︎entire head/neck = 9% ▪︎entire palm including fingers = 1%
▪︎each arm = 9%, each leg = 18% ▪︎entire palm excluding fingers = 0.5%
▪︎anterior trunk = 18%, posterior trunk = 18%
▪︎genitalia = 1%

Question 4

Burns parkland formula and fluids

Answer 4

Initial fluid resuscitation:
*indicated for any patient w/ >15% TBSA
*fluid requirement during initial 24h

Parkland formula ⇢ 4mL x %TBSA x weight(kg)
▪︎first half in first 8h, second half in remaining 16h
▪︎Lactated Ringer’s typically
*modify fluids to maintain urine output 0.5mL/kg/h

Question 5

Burns tx

Answer 5

Immediate measures ⇢ ABC’s
*airway: intubation indicated for known/suspected
inhalation injury or >30-40% TBSA, DO NOT DELAY!!
*obtain vascular access

Immediate burn care:
*remove any burnt clothing/jewelry/obvious debris
*cool burns w/ cool water or saline-soaked gauze
*NEVER ICE
*maintain body temperate ≥95°F (35°C)

Pain management: IV morphine
LABS: CBC, electrolytes, BUN & creatinine, glucose, VBG, carboxyhemoglobin

Prophylaxis: tetanus update if indicated, topical antibiotics to all nonsuperficial burns
▪︎silver sulfadiazine (SSD), mafenide acetate

Superficial & superficial partial-thickness:
*irrigation, topical moisturizers
▪︎calamine lotion, aloe vera gel
*topical antibiotics
▪︎triple ointment ⇢ bacitracin, neomycin, polymyxin B
*daily cleansing & debridement

Deep partial-thickness, 3rd/4th degree:
*early debridement of burnt, necrotic tissue
*escharotomy &/or fasciotomy if indicated
▪︎impending vascular or respiratory compromise
*skin grafts, topical antibiotics

Question 6

Cellulitis causes, sx, dx, tx

Answer 6

Acute spreading infection of the deeper dermis & subcutaneous tissues

Bacteria entry usually occurs after a break in the skin, such as underlying skin problems, trauma, surgical wounds

Etiologies:
*MC caused by group A strep
*staph aureus

sx
Localized macular erythema (flat margins not sharply demarcated), swelling, warmth, tenderness
Systemic sxs not common
Lymphangitis (streaking)

dx: clinical

tx
Oral abx: cephalexin, dicloxacillin
IV abx: cefazolin
Cat bite: Augmentin
Dog or human bite: Augmentin

MRSA:
PO: clindamycin, doxycycline, TMP-SMX
IV: vancomycin

Question 7

Erysipelas definition, sx, dx, tx

Answer 7

Variant of cellulitis involving the upper dermis & cutaneous lymphatics

Etiologies: group A strep MC

sx
Intensely erythematous, raised area w/ sharply demarcated borders, tenderness, warm
MC involves LE, face, or skin w/ impaired lymphatic drainage
*Milian sign: ear involvement
Often associated w/ systemic sxs: fever, chills, leukocytosis

dx: clinical

tx
PO: penicillin, amoxicillin, cephalexin
IV: cefazolin, ceftriaxone
MRSA: vancomycin

Question 8

Impetigo bullous vs non-bulbous: definition, sx, dx, tx

Answer 8

Highly contagious superficial vesicopustular skin infection

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

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 or gram stain/would 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 9

Bullous Pemphigoid definition, sx, dx, tx

Answer 9

Autoimmune disorder leading to blister formation & severe pruritis – primarily seen in the elderly

Type II hypersensitivity reaction – IgG autoantibodies against hemidesmosomes & basement membrane zone causing subepidermal blistering; drug-induced (loop diuretics, metformin)

sx
Prodrome: pruritis w/ eczematous or urticarial plaques

Tense large bullae that don’t rupture as easily MC involving the groin, axilla, trunk, & flexural surfaces
*blister roof contains epidermis

PE: (-) Nikolsky sign (no epidermal detachment)

dx
Skin bx w/ direct immunofluorescence gold standard: linear C3 & IgG along the dermal-epidermal junction, subepidermal blisters, eosinophilia
ELISA: autoantibodies against BP antigen 230 & 180

tx
Topical steroids first line for mild disease or applied to early lesions to prevent blisters
- antihistamines for pruritis

Question 10

Erythema Multiforme defintion, sx, dx, tx

Answer 10

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

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

tx: self limited

Question 11

SJS & TEN definition, sx, dx, tx

Answer 11

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

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

dx: clinical

tx
PROMP DC OF ALL POSSIBLE INCITING MEDS!!!
*if underlying infectious etiology 🡪 treat
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)

Question 12

Lyme Disease defintion, sx, dx, tx

Answer 12

Borrelia burgdoferi

Transmission: Ixodes scapularis (deer tick)
MC in northeast states

sx
Early localized (3-32d after bite): erythema migrans (red annular lesion w/ central clearing), fever, malaise, HA, myalgias, arthralgias

Early disseminated (3-10wks after bite): multiple erythema migrans lesions, CN palsies (esp. 7, lasts 2-8wks then resolves), fatigue, myalgia, HA, occasionally meningitis (stiff neck) or carditis (AV block)

Late disseminated (months-yrs after bite): monoarticular arthritis of large joint (knee in >90%), CNS involvement including chronic demyelinating encephalitis, polyneuritis, memory problems (rare in children)

dx
EIA, if ⊕ ⇢ western blot to confirm
⊕ = 2/3 IgM bands, 5/10 IgG bands
*IgM peaks @3-6wks, IgG weeks-months later
LP (meningitis): 10-150 WBC/mm3, <10% segmented neutrophils, ⇡ protein, normal glucose
EKG: heart block (pts w/ disseminated)
Joint aspiration: WBC 25,000-80,000/mm3 & ⊕ Lyme PCR of joint fluid

tx
Early localized: doxycycline x14-21d

Early disseminated: doxycycline x21d

Jarisch-Herxheimer Reaction: transient fever, HA, myalgias after therapy is started

Question 13

Rocky Mountain Spotted Fever definition, sx, dx, tx

Answer 13

Rickettsia rickettsia

Transmission: dog tick (Dermacentor variabilis), wood tick (Dermacentor andersonii), Lone star tick (A. americanum)

sx
Early: high fever, myalgia, HA (w/ photophobia), V/D, abdominal pain

RASH (2-6d after fever onset): begins on ankles/wrists 🡪 trunk (within hours) & palms/soles
*initially blanching, erythematous, macular
*becomes petechial then hemorrhagic

Other organ systems: vascular leak causing edema, hypovolemia, & hypotension; conjunctivitis, splenomegaly, pneumonitis, meningitis, confusion

dx
Clinical: fever + rash + hx of tick exposure
Labs (vasculitis): thrombocytopenia, ⇣ Na, mild leukopenia, proteinuria, mildly abnormal LFTs, hypoalbuminemia, hematuria

Serology: indirect fluorescent or latex agglutination antibody (not ⊕ until 7-10d after onset); PCR from whole blood/skin biopsies (⊕ 1st week of illness)

tx
SUPPORTIVE; anticipate complications (hypotension, thrombocytopenia, DIC, hypoalbuminemia, hyponatremia)

DOXYCYCLINE x7-10d; alt – chloramphenicol
*continue until pt is afebrile x3d

Question 14

Perioral Dermatitis MC, sx, dx, tx

Answer 14

MC seen in young adult women (20-45)

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

dx: clinical

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

Question 15

Contact Dermatitis irritant vs allergic: defintion, sx, dx, tx

Answer 15

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 and patch testing for allergy testing

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

Question 16

Atopic Dermatitis (Eczema) definition, sx, tx, tx, atopic triad

Answer 16

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

Atopic Triad:
*eczema + allergic rhinitis + asthma

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

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

Question 17

Seborrheic Dermatitis defintion, sx, dx, tx

Answer 17

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

dx: clinical

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

Question 18

Pressure Injury (Decubitus Ulcer) definition

Answer 18

Ulcers resulting from vertical pressure commonly seen on bony prominences (sacrum, calcaneus, ischium)

Question 19

Pressure Injury (Decubitus Ulcer) stages 1-4

Answer 19

Stage I Superficial, nonblanchable redness that does not dissipate after pressure is relieved

Stage II Epidermal damage extending into the dermis; resembles a blister or abrasion

Stage III Full thickness of the skin & may extend into the subcutaneous layer

Stage IV Deepest; extends beyond the fascia, extending into the muscle, tendon, or bone
If slough or eschar obscures the extend of tissue loss, this is an unstageable ulcer

Question 20

Pressure Ulcer tx

Answer 20

Wound care w/ moist wound environment; pain control (opioids if severe)

Debridement of necrotic tissue is present; negative pressure wound therapy
Optimize nutrition (protein & caloric intake, esp. stages 3/4)

Pressure redistribution: position & re-position & using support surfaces (air-fluidized beds, powered mattresses)

Stage 1: transparent film for protection

Stage 2: dressing that maintain a moist wound environment – transparent films or occlusive dressings (hydrocolloids or hydrogels) if there is no infection present

Stage 3/4: debridement of necrotic tissue (mechanical, surgical, enzymatic); surgical debridement for thick eschars or extensive tissue necrosis

Question 21

Scabies definition, sx, dx, tx

Answer 21

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 22

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

Answer 22

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 23

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

Answer 23

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

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

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 24

Pediculosis Corporis “body lice” defintion, sx, dx, tx

Answer 24

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

sx
Pruritis & excoriations

dx: clinical

tx
Hygiene improvement first line
Permethrin 5% cream

Question 25

Exanthematous Drug Eruption definition, sx, dx, tx

Answer 25

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

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
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 26

Angioedema definition, sx, dx, tx

Answer 26

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

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)

dx
If there is no information to suggest an external cause & the patient has isolated angioedema 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 27

Angioedema Urticaria (Hives) definition, sx, dx, tx

Answer 27

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

Type I (IgE) immediate hypersensitivity reaction

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)

dx: clinical

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 28

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

Answer 28

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

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 29

Rubeola (Measles) sx, dx, tx

Answer 29

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

Question 30

Scarlet Fever sx, dx, tx

Answer 30

Etiology: group A strep

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: clincial

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

Question 31

Rubella sx, dx, tx

Answer 31

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 32

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

Answer 32

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

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 33

Roseola Infantum MC, sx, dx, tx

Answer 33

Etiology: MC caused by HHV-6; less commonly HHV-7

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)

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 34

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

Answer 34

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 35

Herpangina MC, sx, dx, tx

Answer 35

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

Question 36

Mumps MC, sx, dx, tx

Answer 36

Etiology: paramyxovirus

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
upportive: acetaminophen, ibuprofen, analgesics
Complications: epididymo-orchitis MC

Question 37

Varicella Zoster Virus shingles vs chicken pox definition

Answer 37

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)

Question 38

Varicella Zoster Virus shingles vs chicken pox sx

Answer 38

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

Question 39

Varicella Zoster Virus shingles vs chicken pox dx

Answer 39

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

Question 40

Varicella Zoster Virus shingles vs chicken pox tx

Answer 40

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 41

Herpes Simplex Virus 1 vs 2 definition

Answer 41

HSV 1 – cold sores
Transmission: direct contact w/ contaminated saliva or other infected bodily secretions

HSV 2 – genital herpes
Transmission: sexually transmitted

Question 42

Herpes Simplex Virus 1 vs 2 dx

Answer 42

HSV 1:

Primary lesions:
*most are asxs but may cause tonsillopharyngitis in adults & gingivostomatitis in children
*Herpetic Whitlow: herpes of the finger

Secondary lesions:
*Herpes Labialis (cold sore): prodromal sxs (pruritis, burning, tingling, pain) followed by grouped vesicles on an erythematous base; crust over before healing

HSV 2 (genital herpes):

Prodrome: burning, paresthesias, numbness; dysuria, fever

Rash: multiple, shallow, tender ulcers; grouped vesicles on an erythematous base; inguinal LAD

Question 43

Herpes Simplex Virus 1 vs 2 dx and tx

Answer 43

dx
PCR
Tzanck smear: multinucleated giant cells

tx
HSV 1:
Orolabial: PO valacyclovir (2g BID x1d)
HSV 2:
Acyclovir, valacyclovir, famciclovir

Question 44

Brown Recluse Spider Bite MC, sx, tx

Answer 44

MC in southwestern/midwestern US
Spider: violin pattern

sx
Local effects: local burning/erythema for 3-4hrs 🡪 blanching of affected area (due to vasoconstriction) 🡪 erythematous margin around the ischemic center “red halo” for 24-72hrs 🡪 hemorrhagic bulla that undergoes eschar formation
10% may develop skin necrosis

Systemic effects: fever, chills, N/V, morbilliform rash

tx
Local wound care + pain control
- local wound care: clean w/ soap & water, cold packs, elevation (most heal spontaneously within days to weeks)
- pain control: NSAIDs (opioids if severe); tetanus prophylaxis if needed

Question 45

Black Widow Spider Bite sx and tx

Answer 45

Spider: red hourglass shape

PATHO: produces a neurotoxin

sx
Local sxs: pain at bite site

Systemic & neurologic sxs: onset within 30min-2hrs – muscle pain (most prominent feature), spasms, rigidity

Usually self-limited w/ resolution within 1-3d

PE: blanched circular patch w/ a surrounding red perimeter & central punctum (target lesion)

tx
Mild: wound care + pain control – soap/water, NSAIDs, opioids
Moderate to severe: muscle relaxants (BDZs, methocarbamol)
Antivenom reserved for pts not responsive to above

Question 46

Pilonidal Disease definition, sx and tx

Answer 46

Results from an abscess, or sinus tract, in the upper part of the natal (gluteal) cleft

Pilonidal means “nest of hair” – a hair in the natal cleft allows hair to be drawn into the deeper tissues via negative pressure caused by movement of the buttocks, follicular occlusion from stretching, & blocking of pores w/ debris

MC seen in pts in late teens/early 20s; male predominance

Less frequently seen in children & >45yrs

sx
3 distinct clinical presentations:
*Asymptomatic: painless cyst or sinus at the top of the gluteal cleft

*Acute Abscess: severe pain, swelling, discharge from the top of the gluteal cleft that may or may not have drained spontaneously

*Chronic Abscess: persistent drainage from a sinus tract at the top of the gluteal cleft

dx: clinical

tx
Acute: prompt I&D

*abx only needed if cellulitis suspected (cefazolin + metronidazole or Augmentin)

Chronic: surgical excision