The "red umbilicus": a diagnostic sign of cow's milk protein intolerance.

Introduction: Red umbilicus is considered to be an infectious disease typical of neonates. In our experience, umbilical erythema could be due to cow's milk protein intolerance (CMPI).

Aims: To evaluate the frequency and clinical significance of umbilical erythema in a series of consecutive children referred for suspected CMPI.

Patients And Methods: Seven hundred ninety-six consecutive patients (median age, 18 months) referred for suspected CMPI diagnosis were studied. CMPI diagnosis was based on the disappearance of symptoms on elimination diet and their subsequent reappearance on double-blind placebo-controlled cow's milk challenge.

Results: CMPI was diagnosed in 384 patients: 120 with respiratory, 75 dermatologic and 198 gastroenterological symptoms. Although some patients showed more than 1 type of symptom, whether gastroenterological, dermatologic or respiratory, they were classified in 1 category only according to the main reason for referral to the outpatients clinic. Umbilical erythema was observed in 36 patients (median age, 10 months): 16 (8%) with gastroenterological symptoms, 9 (7.5%) with recurrent asthma and 11 (15%) with atopic dermatitis. None of the symptomatic controls without CMPI had umbilical erythema. On elimination diet, the erythema disappeared within the second week. On CMPI challenge, it reappeared within 24 hours.

Conclusions: Umbilical erythema can be a sign of food intolerance and can be a useful diagnostic tool for CMPI.