Pet shop cleaning tanks

Bug: Mycobacterium marinum

Treatment: Clarithromycin

Bug: Pasturella multocida

Treatment: Penicillin

Ingestion of raw oysters in patients with cirrhosis

Hemorrhagic bullae, rapidly spreading cellulitis

Bug: Vibrio vulnificus

Treatment: ceftazidime

Bug: Propionibacterium acnes

Pathophysiology: inflammation of sebaceous glands resulting in pustules called comedones

Treatment: benzoyl peroxide, topical antibiotics, corticosteroids, others

Cellulitis

Bug: Group A Strep, Staph aureus

Pathology: rapidly spreading edema, heat, redness. Involves dermis and subq fat. May have cutaneous vesicles, bullae, hemorrhage

Tx: antibiotics against staph and strep

Necrotising fasciitis

Bugs: Strep pyogenes, S. aureus

Pathology: pain disproportionate to exam findings. Will have systemic symptoms like WBC elevation, tachycardia. Will have hemorrhagic bullae, skin necrosis, gas in tissue, hard subq

Tx: surgical debridement

Gas Gangrene

Bug: Clostridium perfingens

Toxin: alpha toxin, a lecithinase

Pathology: severe pain, rapidly spreading toxemic infection from PREVIOUS TRAUMA Dx: gas in soft tissue in radiolo gy

Rx: surgical debridement, antibiotics

Scabies

Bug: fungus, Sarcoptes scabiei

Pathology: tunneling in the stratum corneum causes diffuse pruritic eruption. Thin burrow tracts seen

Tx: topical scabicides, treat all close contact. Also give oral-antiparasitic

Walking barefoot on beach - dermatitis with intense itching

Carbuncle

Definition: large extensive sub-q abscess

Bug: S. aureus (furuncles/carbuncles), P. aeruginosa ("hot tub")

Greenhouse worker or gardener

Bug: fungus, Sporothrix schenckii

Presentation: Swollen cutaneous lesion due to plant-related trauma

Herpes

Bug: Herpes simplex virus

Herpes labialis - oral mucosa

Herpes genitalis - papules on the outer surface of genitals

Herpes whitlow - infection on fingers or thumbs

Chicken Pox

Bug: Varicella zoster

Presentation: vesiculate rash, starts in hair and behind ears, spreads downward. Major concentration on trunk, sparce on limbs. The rash is asynchronous (new crops of rashes develop). Fever after rash

Shingles

Bug: varicella zoster

Presentation: painful outbreak of vesiculate lesions along 1-3 dermatomes

Measles (rubeola)

Bug: measles virus

Presentation: seasonal (deep winter to early spring). Begins with cough, coryza, conjunctivitis, fever. Onset of rash -blotchy red rash, starts on face, spreads downward. Confluent rash on face and upper trunk, discrete on lower extremities

Roseola

Bug: human herpesvirus 6

Presentation: clind 5 mo-3 years of age, high fever for 3 days, maculopapular facial rash after fever

Verrucae

Bug: human papilloma virus

Pathology: basal layer infection, proliferation of spinous layer

Dx: biopsy or clinical appearance

Tx: spontaneous resolution. Cryosurgery, imiquimod

Mycoses (fungal infection)

Example: Tinea versicolor

Bug: Pityosporum ovale

Presentation: scaly patches on chest and back showing changes in pigmentation (hypo or hyper)

Dx: KOH under slide = spaghetti and meatballs

Tx: anti-fungals

Dermatophytosis (tinea)

Bugs: tinea subclasses

microsporum - hair and skin

trichophyton - hair, nails, skin

epidermophyton - skin and nails

Presentation: Itchy skin lesions spreading out from the periphery. Margins usually erythematous, can appear everywhere on the body

Dx: KOH under slide - spaghetti and meatballs

Hot tub folliculitis

P. aeruginosa

Acneiform eruption usually on back and chest of hair follicles. Can become furuncles or carbuncles

Bugs: Group A strep. S. aureus

Presentation: gold, honey-colored crusted superficial infection in kids (kidney: can cause post-strep nephropathy)