OBJECTIVE To describe clinical and immunohistochemical findings in patients with cutaneous Langerhans cell histiocytosis (LCH) beginning in the first 3 months of life and to define predictors of disease evolution. METHODS Observational retrospective survey from July 15, 1989, to April 30, 2007. METHODS Referral center in pediatric dermatology. METHODS Thirty-one patients with a diagnosis of cutaneous LCH in the first 3 months of life and no previous visceral LCH. METHODS Cutaneous lesion characteristics, regulatory T-lymphocyte density, and E-cadherin expression were assessed. Data were compared between the patient groups with self-regressive vs non-self-regressive forms of cutaneous LCH. Pathologic analysis was performed blinded to patient group. RESULTS Self-regressive cutaneous LCH was found in 21 patients and non-self-regressive cutaneous LCH in 10 patients. Monolesional forms, necrotic lesions, hypopigmented macules at presentation, and distal topography of limb lesions were seen only in patients with self-regressive cutaneous LCH. Regulatory T-lymphocyte density correlated with interleukin 10 expression in lesions (r = 0.77, P = .003) but was not predictive of disease evolution. E-cadherin expression by Langerhans cells was found in 7 patients with disease limited to the skin whether self-regressive or not. One patient with secondary disseminated disease showed loss of E-cadherin expression in Langerhans cells. CONCLUSIONS Some morphologic traits of skin lesions can orient the diagnosis to a self-regressive form of cutaneous LCH. Regulatory T-lymphocyte density does not seem to be predictive of disease evolution. E-cadherin expression seems to be an indicator of limited skin disease but not of disease regression. Additional immunohistochemical study is required to confirm these data.