History
Ecthyma usually arises on the lower extremities of children, persons with diabetes, and neglected elderly patients. During wartime in tropical climates, ecthymatous ulcers are commonly found on the ankles and dorsi of the feet.
Physical Examination
Ecthyma begins as a vesicle or pustule overlying an inflamed area of skin that deepens into a dermal ulceration with overlying crust. The crust of ecthyma lesions is gray-yellow and is thicker and harder than the crust of impetigo. A shallow, punched-out ulceration is apparent when adherent crust is removed. The deep dermal ulcer has a raised and indurated surrounding margin.
Ecthyma lesions can remain fixed in size (sometimes resolving without treatment) or can progressively enlarge to 0.5-3 cm in diameter.
Ecthyma heals slowly and commonly produces a scar.
Regional lymphadenopathy is common, even with solitary lesions.
Complications
Ecthyma rarely produces systemic symptoms.
Invasive complications of streptococcal skin infections include cellulitis, erysipelas, gangrene, lymphangitis, suppurative lymphadenitis, [8] bursitis, [6] lobar pneumonia, [6] and bacteremia.
Nonsuppurative complications of streptococcal skin infections include scarlet fever and acute glomerulonephritis. Prompt antibiotic therapy does not appear to reduce the rate of poststreptococcal glomerulonephritis. Streptococcal toxic shock syndrome has been reported. [6]
Possible sequelae of secondary untreated S aureus pyodermas include cellulitis, lymphangitis, bacteremia, osteomyelitis, and acute infective endocarditis. Some S aureus strains produce exotoxins that can lead to staphylococcal scalded skin syndrome and toxic shock syndrome.
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Typical ecthyma lesions of the lower extremities.
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The stages of ecthyma: the lesion begins as a pustule that later erodes and ultimately forms an ulcer with adherent crust.
