Described in 1953 1 and then more thoroughly in 1957, 2 Haemophilus influenzae cellulitis has since attracted considerable attention. 3-14 The article by Granoff and Nankervis in this issue (p 1211) emphasizes the heterogeneity of the clinical signs and reports the initial evaluation of bacterial antigenemia and antibody activity in children with this disease. Haemophilus influenzae cellulitis affects young children (range, 3 to 37 months; average, 11 months) without sex predilection. Symptoms develop after a brief, febrile, nonspecific upper respiratory illness. High fever (39.0 to 40.5 C) and a rapidly progressing skin lesion with indistinct margins, induration, tenderness, and purplish discoloration are characteristic. The cheek or periorbital area are involved, invariably unilaterally, in about three-fourths of reported cases; the upper extremities are the next most common site. This clinical picture is not pathognomonic, however, since other bacteria may produce facial cellulitis with purplish discoloration, 15 whereas the purplish hue does