Dermatology pt.3

Edematous, expanding warm plaque that may present with fever and can involve the lower leg

Cellulitis

Organisms that cause cellulitis

Gram + cocci (Group A strep and S.aureus)

What would you see on a lab of someone with cellulitis

Leukocytosis

Neutrophilia

What is the treatment for cellulitis

Systemic ABX

Which antibiotics would you prescribe with someone with cellulitis caused by MRSA

TMP-SMZ, doxycycline

What ABX would you prescribe with someone with cellulitis caused by MSSA

PO: Cephalexin (Keflex) 500 mg QID, 5-10 days

Superficial form of cellulitis cause by Strep Pyogenes

Erysipelas

What makes erysipelas different from cellulitis

-circumscribed with raised border

-central face frequently involved

Which do you treat more seriously, cellulitis or erysipelas?

Erysipelas

Treatment for erysipelas

IV ABX (vancomycin or PCN G)

Abcess that evolves from a staph folliculitis

Furnuncle

Interconnecting furnuncle across contiguous hair follicles

Carbuncle

Characterized by fluctuance in the the center

Abcess

Treatment of abcess

Incision and drainage

Honey colored crusts and erosions

Impetigo

Scattered satellite lesions that commonly occur adjacent to site of S aureus colonization

Impetigo

Treatment for impetigo

Topical ABX: Mupirocin 2% applied TID, 5 days

What is caused by the gram + bacteria Corynebacterium minutissimum

Erythrasma

What appears bright coral red on a woods lamp exam

Erythrasma

Treatment for Erythrasma

Clindamycin 1% lotion +

Benzoyl peroxide wash

Pitted Keratolysis is caused by the bacteria ____ that lives on plantar feet and produces proteases that digest keratin

Kytococcus sedentarius

Treatment for pitted keratolysis

BP wash and topical clindamycin

Pustules on erythematous base that become confluent and may erode

Candidiasis

Characteristic findings of candidias is

Satellite lesions

What KOH finding confirms candidiasis

Pseudohyphae and yeast forms

Treatment for candidiasis

Wash with BP + use antifungal powder

Fx: Antifungal cream: Nystatin, ketoconazole

Specific type of fungi capable of infecting nonviable keratinized cutaneous structures (hair and nail)

Dermatophytes = tinea

Triphophyton rubrum is the most common cause of

Skin and nail dermatophytosis

Tinea versicolor is from the yeast

Malassezia

What is KOH positive for in dermatophytoses

Septated hyphae, looks like bamboo

Tinea mannum

Hands

Tinea cruis

Groin

Tinea unguium

Nails

General presentation of dermatophytoses

Erythematous patch with fine scaling in center and increased scaling at border

Treatment for epidermal dermatophytoses

Ketaconazole, terbinafine topicals

Treatment for hair and nail dermatophytoses

Terbinafine 250 mg daily

-continue at least one week after clearing

Lab results for tinea (Pityriasis) versicolor

Spaghetti and meatballs

Treatment for tinea versicolor

Selenium sulfide 2.5% shampoo

Ketoconazole shampoo

Tinea nigra is caused by the pigmented fungus ___, is picked up from the soil and has branching septate hyphae on microscopy. You can treat it with ____

Hortaea weneckii

Topical azole or alcohol gel sanitizer

Verrucae is caused by what virus

HPV

Warts have what characteristic when top is removed

Red or brown dots

treatment for warts

Cryotherapy (liquid nitrogen)

Condyloma acuminata is caused by what HPV

6 and 11

Protrudant, cauliflower like, pedunculated

Genitals warts

What may you think gential warts are?

SCC

Treatment for condyloma acuminata

Imiquimod 5% cream, Podophylox 0.5% solution applied by patient

What can the clinician apply to condylar acuminata in office that is basically like a chemical peel

Podophyllin 10-25%

Classically grouped vesicles on a erythematous base on skin or mucous membranes

Herpes simplex virus

HSV1 in

Labialis

Herpetic Whitlow

HSV2 in

Urogenital

Neonatal

Diagnostic testing for HSV

Viral culture/Tzanck smear

Treatment for HSV

Oral antiviral : Valacyclovir, acyclovir

Disseminated viral infection, most commonly HSV-1, most often in patients with atopic dermatitis

Eczema herpeticum

What is considered on of the few dermatological emergencies

Eczema herpeticum

Treatment for eczema herpeticum

Oral valacylovir 1g BID for 10-14 days

What is caused by pox virus and is common in children

Molluscum contagiosum

Dome shaped, waxy pearly papules, 2-5 mm in diameter, umbilicated

Molluscum contagiosum

DDX for molluscum contagiosum

Flat warts, SCC, condyloma acuminata

Treatment for Molluscum contagiosum is usually self limited, however what can be used

Cryotherapy

Cantharadin (beetle juice)

Systemic viral infection caused by Coxsackievirus that is most common in first 10 years of life and usually is on the palms, soles, mouth

Hand, foot, mouth disease

Varicella zoster virus is from

Human herpes virus 3

Primary infection of HHV3 causes

Chicken pox

When HHV3 is reactivated, it is then

Herpes zoster (shingles)

Pruritic lesions that appear in crops and start on the head and then move inferiorly, have clear vesicles on a erythematous base "dew drops on a rose petal"

Primary varicella

Follows a dermatome, unilateral

Herpes zoster

How to detect zoster opthalmicus

Hutchinson sign

What is Hutchinson sign

Vesicles on tip of nose or inner eye

Ramsay hunt syndrome is

varicella zoster virus infection in geniculate ganglion of CN Vll, facial nerve

Unilateral facial weakness and vesicles in the ear canal

Ramsay hunt syndrome

When treating varicella (chicken pox) it is important to

Isolate until primary lesions have crusted

Antivirals for varicella

Acyclovir up to 800mg 4x daily for patients > 12

Valacylovir 1gm per dose 3x daily for 5-7 days > 2 yo

For herpes zoster, begin antivirals writhing ____ hours of onset of rash, continue for 7 days or until lesions crusted over

72

What is preferred for treating herpes zoster

Valacyclovir 1g 3x for 7 day

What antiviral is not approved for use in <18 yo

famciclovir

What is a complication of VZV

Postherpetic neuralgia (usually >60)

Treatment for postherpetic neuralgia

Gabapentin along with topical capsaicin cream

Benign black/brown papules or plaques with a velvety warty surface

Seborrheic Keratoses

Appear to be "stuck on"

Seborrheic keratoses

Small hyperkerotic macules or papules that feel like sandpaper

Actinic keratoses

Premalignant (1:1000 lesions per year progress to SCC)

Actinic keratoses

Treatment for a singular actinic keratoses

Cryotherapy

Field treatment for multiple actinic keratoses

Fluorouracil 5% cream

Since there is usually an AK ____ should always be excised and sent for dermatopathology

Cutaneous horn

acrochordon (skin tags) are benign and usually appear on the

Axillae, neck, groin, eyelids

Dome shaped nodule with central keratotic plug, rapidly growing locally destructive skin tumor

Keratoacanthoma

Bowens disease

squamous cell carcinoma in situ

Sharply demarcated, scaling, hyperkertotic, can be crusted

Squamous cell carcinoma in situ

SCCIS: Once invasion occurs, nodular lesions appear within the plaque and the lesion is then commonly called

Bowen carcinoma

SCCIS gold standard for diagnosis is

Skin biopsy

Untreated, SCCIS will progress to

Invasive SCC

Treatment for SCCIS

MOHS - highest cure rate

Although MOHS is gold standard, what topical chemotherapy can be applied to SCCIS

5-FU cream

Malignant tumor of keratinocytes arising in the epidermis, has spread beyond the epidermal-dermal junction

Invasive SCC

Majority of invasive SCC is ____ which is hard on palpation and has hyperkeratosis

Differentiated

Treatment for invasive SCC is ALWAYS

Surgery , MOHS

For invasive SCC, follow up

Every 3 moths for TBSE/year then twice a year

Most common type of cancer in humans

BCC

Common on face and is slow growing and there is no tendency to metastasize

BCC

Waxy,pearly papule/nodule or erythematous patch with central scab that tends to bleed easily and may to may not have telangectasia

BCC

What is preferred treatment for BCC?

Surgical excision