title: Cutaneous S100-negative, CD1a-positive histiocytosis successfully treated with combination therapy of oral methotrexate and corticosteroid.
abstract: S100-negative, CD1a-positive histiocytosis is a rare histiocytic disorder characterized by proliferation of histiocytic cells possessing a phenotype of epidermal Langerhans cells except for the lack of S100 expression and Birbeck granules. We report the case of a Japanese man suffering from S100-negative, CD1a-positive histiocytosis. The patient showed numerous smooth erythematous 5-10-mm papules/nodules on most of his body. The key histopathological feature was the presence of dermal infiltrates of non-epidermotropic S100-negative CD1a-positive mononuclear cells. No systemic involvement was detected. Initially bath-psoralen plus ultraviolet A therapy was effective, but the lesions became recalcitrant to this treatment. Methylprednisolone pulse therapy followed by low-dose methotrexate (up to 30 mg/week) in combination with prednisolone (15 mg/day) effectively controlled the skin lesions.
authors.affiliation: Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Takahashi
authors.affiliation: Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kaneta
authors.affiliation: Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Wakana
authors.initials: W
authors.lastname: Nomura
authors.affiliation: Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ohishi
authors.affiliation: Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Uehara
authors.affiliation: Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Honma
authors.affiliation: Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Akemi
authors.initials: A
authors.lastname: Ishida-Yamamoto
authors.affiliation: Department of Dermatology, Obihiro-Kosei General Hospital, Obihiro, Japan.
authors.forename: Hidetsugu
authors.initials: H
authors.lastname: Sato
authors.affiliation: Takagi Dermatological Clinic, Obihiro, Japan.
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Takagi
authors.affiliation: Department of Dermatology, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Iizuka
mesh_terms: D000328:Adult; D018949:Antigens, CD1 / Q000378:metabolism; D003879:Dermatologic Agents / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005938:Glucocorticoids / Q000627:therapeutic use*; D015614:Histiocytosis / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D011239:Prednisolone / Q000627:therapeutic use*; D009418:S100 Proteins
chemical_list: D018949:Antigens, CD1; C419393:CD1a antigen; D003879:Dermatologic Agents; D005938:Glucocorticoids; D009418:S100 Proteins; D011239:Prednisolone; D008727:Methotrexate
keywords: CD1a; S100 protein; corticosteroid; histiocytosis; methotrexate; ultraviolet therapy