Parasitic Infections, Inflammatory Nodules & Ulcers (Exam 1)

Scabies

-Caused by Sarcoptes

-Transmitted by skin-skin contact, or from clothing or bedding

-Often seen in close living quarters (Nursing homes, army, overcrowding)

-Females burrow into skin and deposit eggs and feces

-Eggs hatch within 3-4 days

-Hypersensitivity

Clinical Signs of Scabies

-Sensitivity occurs after 1 month

-Intense pruritus with minimal skin findings

-Found at finger webs, wrist creases, axilla, lower abdomen, groin feet

-Often burrows are only found on feet because they have been scratched off in other locations

-Pruritus most severe at night time

-Scratching may cause secondary infection

-Norwegian Scabies: frequently in elderly and others that are IC (Associated with high mites; thick scale; affect majority of body)

Diagnosis of Scabies

-Ask patient if they have severe itching especially at night
-Any recent vacations, hotel stays, sexual partners
-Scabies prep: Scrape burrow

Treatment of Scabies

-Permethrin 5%: Applied HS, rinse in AM; repeat in 1 week
-Crotamiton: Apple HS, repeat in 24 hours; shower 48 hours after last application
-Topical corticosteroids for symptoms
-Ivermectin: Oral medication
-All clothing, bedding, towels must be washed
-Fingernails trimmed
-Family & sexual partners should be treated

Lice

-Caused by ectoparasites
-Head: Pediculosis humanus capitis
-Body: Pediculosis humanus corporis
-Public: Phthirus pubis

Pediculosis Capitis

-Epidemiology: Mostly in kids; seen in overcrowded areas

-Transmitted by shared use of hats or combs

-All socioeconomic classes in school

Clinical Manifestations of Pediculosis Capitis

-Intense pruritus of scalp

-Small, white, oval-shaped capsules firmly attach to hair shaft close to hair follicle

-Easiest to see above ears and at nape of neck

-Hair appears lusterless, dry and not as shiny

-Mite has an elongated body that conforms to hair shaft

Treatment of Pediculosis Capitis

-Destruct lice and ova
-OTC: Permethrin 5% or 1%; repeated in 1 week
-RX: Spinosad (4 years); Ivermectin (6 months); Malathion (6 months); Benzoyl Alcohol (6 months)
-Remaining must be removed by comb

Pediculosis Corporis

-Not commonly found because mite feeds and jumps off body
-Look under belts, collars, or bedding
-Intense pruritus and scratching
-Papular urticaria at site of mite bite
-Treat by disposing infested clothing

Pediculosis Pubis

-May be acquired by sexual transmission or sharing bed
-Seen around genitals, lower abdomen, eyelashes
-Pruritus
-Will see nits on hair and lice on skin

Treatment of Pediculosis Pubis

-Permethrin cream
-Treat sexual partners
-Bedding and clothing need to be washed
-Eyelashes should be coated with petroleum jelly for 8 days

Bed Bugs

-Found in crevices of beds or furniture

-Bites tend to occur in lines or clusters

-May develop large wheals accompanied by itching and inflammation

-TX with anti-pruritics and steroid creams

Erythema Nodosum

-Tender, erythematous nodules appear on lower legs

-Lasts 6 weeks, may recur

-Associated with infections (Strep), sarcoidosis, Behcet disease and IBD

-May also be associated with pregnancy or OCP

Signs & Symptoms of Erythema Nodosum

-Subcutaneous swelling that is very tender

-May be preceded with fever, malaise, and arthralgias

-Located mostly on anterior surface of lower legs

-Often starts pink to red and then regresses

Treatment of Erythema Nodosum

-ID underlying cause

-NSAIDS

-Postassium Iodide

-Bed rest

-Oral corticosteroids

Course of folliculitis

-Can progress to deeper infection with abscess (Furuncle)
-Carbuncle: deeper infection with multiple hair follicles
-Many types will recur unless conditions are corrected
-TX: IND; Warm soaks; ABX (Doxy, bactrim, clinda)

Epidermal Inclusion Cyst (Sebaceous cyst)

-Oil producing gland gets clogged and fills with sebum and keratin

-May get infected or rupture

-Round, hard, mobile papule, nodule

-Overlying punctum

-Maladorous

Treatment for Epidermal Inclusion

-If lesion is Non-Inflamed: do excision; IND can lead to return of this

-Inflammed: IND; intralesional steroid; topical & oral ABX (If infected)

Photodermatitis

-Skin reaction due to UV radiation

-Often caused by drugs or Lupus

Signs & Symptoms of Photodermatitis

-Erythema, edema, possible vessiculation

-If severe enough may be accompanied by systemic symptoms

-Key to diagnosis is the localization of rash

-Must distinguish from contact dermatitis, lupus

Treatment of Photodermatitis

-Sunscreens & clothing
-D/C any offending medication
-treat similar to acute dermatitis (High potent corticosteroids)
-Aspirin
-Oral corticosteroids