Blistering distal dactylitis is a cellulitis of the fingertip caused by group A β-hemolytic Streptococcus or, less often, S aureus infection in children from infancy to teenage years. The typical lesion is a seropurulent, fluid-filled, painful, tense blister with surrounding erythema located over the palmar fat pad on the distal portion of a finger or toe. Polymorphonuclear leukocytes and gram-positive cocci can be found in the Gram stain of the purulent exudate from the lesion. The differential diagnosis includes bullous impetigo, burns, friction blisters, paronychia, felon, and herpetic whitlow.
Blistering Distal Dactylitis. Blistering rash of the distal fingers with surrounding erythema typically caused by Streptococcus. Note the location of the rash over the volar finger pads. (Photo contributor: Anne W. Lucky, MD.)
Management and Disposition
There is usually a rapid response to incision and drainage of the blister and an appropriate course of oral antibiotic therapy. Consider use of agents active against MRSA (clindamycin or trimethoprim-sulfamethoxazole) if there is a high community prevalence.
Nonpurulent vesicular lesions that become confluent multilocular bullae are characteristic of herpetic whitlow, which should not be drained, and help distinguish it from blistering distal dactylitis.
Topical antibiotics are not recommended.
Blistering Distal Dactylitis. Inflammation and fluid-filled vesicles in a child with blistering dactylitis. (Photo contributor: Lawrence B. Stack, MD.)