Bites and Stings

The most effective treatment to eliminate the lesions seen here:

A Topical steroidsB Oral antibioticsC Treatment of home for

fleasD 5% Permethrin cream to

all household membersE Oral antihistamines

Question 5

Think about distribution (exposure)Bites on face may be atypical

RedPruriticSoft and nontender

Intense, hemorrhagic reaction possibleFleas: some members of household “spared”

Clusters of 3Grass or sand mites: localized blisters

Bites and Stings

More intense reactionErythema and induration

EcchymoticPainfulPruritic

VesciculateCentral necrosis with eschar

Brown Recluse

Spider Bite

Local pain, erythema, edema within 2hrs

Honey BeeStinger in skinReleases venom for an hourScrape horizontally with

fingernail or card

Hymenoptera Stings

Late onset edemaPeak 48-72hrsDelayed hypersensitivityPruritic, painful

TreatmentPaste of meat tenderizer and

waterSymptomatic treatment

Risk of anaphylaxisKnown historyMastocytosisEducation on avoidanceEpiPen

Hymenoptera Stings

TimingYoung childrenChronic/recurrent

DescriptionHighly pruritic papules and wheals

Central punctumVesiculate centrally3-10mm diameter

Resolution: central crust with collarette of scaleAfter 4-6wks: target-shaped macule

Linear or triangular clustersExposed areas

Papular Urticaria

CauseHypersensitivity to fleas, bedbugs, mosquitoesFleas and bedbugs are not seasonal

Only youngest child in family may be affected>1y/o

May experience “reactivation”New bites incite delayed hypersensitivity at old

sites

Papular Urticaria

TreatmentIdentification and

avoidance of insectRepellent

Topical steroidsOral antihistaminesGood hygiene

(secondary infections)

Papular Urticaria

Infestations

CauseMite: Acarus scabiei Burrows beneath skin

Hypersensitivity reaction

Timing4-6 wks after initial contact

DescriptionIntensely pruritic papules, vesicles, pustules,

linear burrowsfingers/ webs of toes, flexor regions, nipples,

waist, groin/buttocks, palms/solesInfants: intense and persistent nodular reaction

Scabies

Excoriation and secondary infectionDiagnosis

ClinicalSkin scrapings: mite, eggs, feces

From linear burrow (black speck)

Treatment5% permethrin (Elimite)All household membersWash all linensRepeat 1 wk later

Scabies

Crab lice (Phthirus pubis)Sexually transmittedEyelashes and pubic hairBites

Bluish, pruritic papules: lower abd and upper thighs

Intense pruritisChildren

Scalp or eyelashes

Lice

Body lice (pediculus humanus corporis)Bedding or clothingBites

Urticarial papulesWaist, neck, shoulders, axillae

Excoriations/ secondary infection

Lice

Head Lice (pediculus humanus capitis)Most commonExcoriations of scalp

and neckOccipital adenopathy

Nits: oval, white 0.5mm dot glued to hairshaftAbove and behind earsNonviable shells may

remain attached after treatment

Lice

Treatment:Pediculicide topically (all household members)

Permethrin creamMalathion lotion (second line…flammable)Lindane: contraindicated in young… neurotoxic

Cleaning of linens/clothingNits:Diluted vinegar rinseFine-toothed comb

Lice

Acne vulgarisDisorder of pilosebaceous apparatus

Cause: UnknownAbnormal follicular keratinizationDriven by androgensPropionibacterium acnes

TreatmentTopical retinoic acid, benzoyl peroxide, abxSevere: oral abx with topical agents

Acne

Other Lesions

The most reliable way to distinguish these lesions from other lesions frequently seen on the sole of the foot:

Question 6

A Black dots indicate corns that have received trauma

B Interruption of dermatoglyphics indicate plantar warts

C Superficial scaling indicates callus formationD Boggy texture indicates plantar warts

HPVFingers, hands, feetPlantar wart: Larger than appearance

Painful w walkingInterrupts dermatoglyphics

Incubation 1-6mosDisappear spontaneously over 5yrsLocal trauma: inoculation of virus

Periungual common

Warts

Characteristic appearanceBlack dots (thrombosed

capillaries)Condylomata acuminata

Anogenital wartsConsider sexual abuse

Controversial <age 3 (vertically acquired)

TreatmentDuct tapeSalicylic acid

Warts

Pox virusDescription:

Dome-shaped papules with waxy surface

Single or multipleMay be pruritic5mm

Location: trunk, face, axillae, genital area

Spread by scratching (linear)

Molluscum Contagiosum

Curdlike core can be expressed from centerCourse: spontaneous remission 2-3yrsTreatment

Watchful waitingCuretting after topical anesthetic

Especially in poorly controlled eczema

Molluscum Contagiosum

Congenital Lesions

Pathological proliferation of mast cells in skinOther organs involved as well

Darier signWhen lesion (or skin) rubbed,

urticaria developsHistamine release following

trauma to superficial mast cellsMay form blisters

75% identified by age 2

Cutaneous mastocytosis

Urticaria pigmentosa (most common form)

Oval or round red-brownMacules, papules, plaquesSolitary or innumerable

ResembleNevi, pigmentary alteration,

CALMsMay be associated with GI

symptomsHypotension in severe cases

Cutaneous mastocytosis

Other organ systems can be affected

TreatmentUsually resolves in childhoodSymptomatic treatment

AntihistaminesImmunosuppresants in

severe casesExtensive workup rarely

needed

Cutaneous mastocytosis

AKA: NevoxanthoendotheliomaPresent at birth (w/in 1st year)Grow slowly and become more yellowBenign proliferation of non-Langerhans cell

histiocytesBrown to yellow color: lipid-laden histiocytesBenign

Juvenile Xanthogranuloma

Primarily in whitesUsually solitary nodular lesion

Multiple small papular lesions possible4% extracutaneous

IrisOther locations

Associations/ComplicationsGlaucomaMyelomonocytic leukemiaNontraumatic Hyphema

Juvenile Xanthogranuloma

No specific gene defectNF-1Urticaria pigmentosaNiemann-Pick

TreatmentWatchful waiting

Resolve 5y/oSurgical excisionSteroids +/- chemo

Juvenile Xanthogranuloma

Abnormal immunityT-Cells, NeutrophilsHigh IgE and eosinophils

Chromosome q4ADVariable expressivity

Job Syndrome

DescriptionPruriticS. aureus superinfectionWeeping, crusting, cutaneous abscessesAbscesses (little pain and inflammation)Mucocutaneous candidiasis

TimingShortly after birth

Job Syndrome

CourseRecurrent focal bacterial

infectionsDecreased bone density

with multiple fracturesLittle pain

With age: scoliosis and coarsening of facial features

TreatmentControl infections

Job Syndrome