-IBIS-1.5.0-
tx
cutaneous system
impetigo
diagnoses
definition and etiology
definition: superficial vesiculopustular skin infection mainly seen in children; also called "impetigo contagiosa" and "ecthyma" (when the impetigo is ulcerative)
etiology: The associated microorganism is primarily Group A beta-hemolytic streptococcus, although staph aureus is being implicated in a growing number of cases (in the past staph was limited to only bullous impetigo). Impetigo is primarily seen in children under 5 years old, and appears on exposed areas like the lower legs, arms or face. The infection may follow trauma to the skin, scabies, insect bites, fungal infections, fleas, various kinds of dermatitis, or may just appear on normal skin.
signs and symptoms
signs and symptoms:
lesions: rapid progression of lesions from maculopapules to vesicopapules or bullae, and a thick, honey-colored, sticky exudate that crusts
itching: scratching can easily spread the infection
ecthyma: localized, shallow, punched-out ulcerations that are covered with a brown-black crust and surrounded by erythematous tissue; may progress rapidly and leave a scar
with either type, there may be fever, malaise and lymphadenopathy
lab findings:
(+) blood findings of infection
may have increased WBC count
(+) culture of staph and/or strep from skin lesion
ASO titer may be useful
course and prognosis
Untreated infection may develop into cellulitis, lymphangitis, or furunculosis and there may be pigment changes and/or scarring of the affected tissues. Acute glomerulonephritis may develop in children after skin infection with strep.
differential diagnosis
herpes zoster
varicella
contact dermatitis
footnotes