Popsicle panniculitis in a 5-month-old child on systemic prednisolone therapy.

To the Editor: Popsicle panniculitis is a type of cold panniculitis that affects the cheeks of young children, is self-limited, and may be mistaken for cellulitis. The diagnosis may be missed unless a detailed history is elicited. We present a 5-month-old child who developed bilateral popsicle panniculitis on his cheeks despite being on systemic prednisolone for a large facial hemangioma. A 5-month-old African-American child being treated for a large facial hemangioma presented to clinic with new painful, indurated, erythematous plaques on both cheeks. He had begun oral prednisolone 10 weeks earlier (3 mg ⁄kg ⁄day initially, tapered to 2 mg ⁄kg ⁄day over the first month, and 1.8 mg ⁄kg ⁄day over the next 6 weeks). Three days prior to presentation, the patient had been given a popsicle by his mother because he was teething. Later that day, he developed tender nodules on his cheeks.On physical examination, the infantwas healthyappearing and afebrile. He had a large midline facial hemangioma on the nose and forehead and erythematous, edematous plaques on both cheeks (Fig. 1). A diagnosis of popsicle panniculitis was made. Within 2 weeks, the lesions fully resolved without therapy, while his prednisolone was decreased to every other day dosing. Popsicle panniculitis is rarely documented, but likely much more common than is reported (1–3). Popsicle panniculitis is a type of cold panniculitis, awell-described condition that usually occurs in neonates and infants following cold injury. Although popsicle panniculitis may sometimes be misdiagnosed as bacterial cellulitis, the clinical appearance and history are generally sufficient to make the diagnosis. Biopsy specimens of cold panniculitis show a lobular mixed inflammatory cell infiltrate, most prominent at the dermo-subcutaneous junction (4,5). Cold panniculitis is self-limited and patients generally fully recover several weeks after exposure. The cold sensitivity declines as children age.Of interest, our patient was on high-dose oral prednisolone therapy for the treatment of his facial hemangioma. Systemic corticosteroid therapy might be expected to suppress inflammation and decrease the likelihood of developing inflammation after cold injury. We doubt that the steroid taper contributed to his panniculitis because the amount of steroid he was receiving had not been decreased over the preceding 6 weeks. To our knowledge, this is the first report of popsicle panniculitis in the setting of systemic corticosteroid therapy. Although the exact mechanism is unknown, the pathogenesis of coldpanniculitismaybe similar to thatof subcutaneous fat necrosis of the newborn (SFN) (6). In SFN, the greater concentrationof saturated fatty acids in the subcutaneous fat of neonates compared with adult subcutaneous fat has been theorized to explain the increased susceptibility to crystallization and necrosis under cold stress (7,8). Our patient is interesting because he developed cold panniculitis despite being on systemic corticosteroid therapy.As popsicle panniculitis resolves spontaneously, we suggest that unnecessarybiopsies or treatmentmaybe avoided by eliciting a careful history in consideration of the physical presentation.