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Pityriasis Amiantacea

      A woman in her early 30s presented with a 2-month history of a spontaneous nonpruritic rash on her frontal scalp, which progressed to her temporal scalp. She had no history of psoriasis, seborrheic dermatitis, or eczema. Examination revealed thick adherent yellow scales on the frontal, temporal, and vertex scalp with associated nonscarring alopecia (Figures 1 and 2).
      Figure thumbnail gr1
      Figure 1Silver/yellow thick adherent scale affecting the frontal and vertex scalp with nonscarring hair loss.
      Figure thumbnail gr2
      Figure 2A plaque of silver/yellow thick adherent scale affecting the left temporal scalp, showing the scales surrounding tufts of hair.
      Clinical examination was consistent with pityriasis amiantacea. Wood lamp examination and fungal culture ruled out tinea capitis. She was treated with topical clobetasol solution and coal tar shampoo, with considerable improvement.
      Pityriasis amiantacea is a rare scalp condition that presents with thick waxy scaling that binds down tufts of hair. It was described by Alibert in 1832 as “La Porrigine Amiantacée” after aminate—the scale around the feathers of young birds that has an asbestos-like appearance.
      • Knight A.G.
      Pityriasis amiantacea: a clinical and histopathological investigation.
      It can occur in children and adults and often presents with temporary nonscarring alopecia in the affected areas.
      • Kwak H.B.
      • Yun S.K.
      • Kim H.U.
      • Park J.
      Pityriasis amiantacea: an epidemiologic study of 44 cases in Korean patients.
      The exact cause is unknown, but it has been associated with psoriasis, seborrheic dermatitis, tinea capitis, atopic dermatitis, as well as tumor necrosis factor-α inhibitor therapy.
      • Kwak H.B.
      • Yun S.K.
      • Kim H.U.
      • Park J.
      Pityriasis amiantacea: an epidemiologic study of 44 cases in Korean patients.
      • Ettler J.
      • Wetter D.A.
      • Pittelkow M.R.
      Pityriasis amiantacea: a distinctive presentation of psoriasis associated with tumour necrosis factor-α inhibitor therapy.
      • Abdel-Hamid I.A.
      • Agha S.A.
      • Moustafa Y.M.
      • El-Labban A.M.
      Pityriasis amiantacea: a clinical and etiopathologic study of 85 patients.
      Diagnosis is often made on the basis of clinical examination and dermoscopy, although other causes, such as tinea capitis, should be ruled out with fungal culture.
      • Verardino G.C.
      • Azulay-Abulafia L.
      • de Macedo P.M.
      • Jeunon T.
      Pityriasis amiantacea: clinical-dermatoscopic features and microscopy of hair tufts.
      Histopathology is usually not required but typically reveals spongiosis, parakeratosis, and migration of lymphocytes into the epidermis.
      • Knight A.G.
      Pityriasis amiantacea: a clinical and histopathological investigation.
      It typically responds to topical corticosteroids, keratolytic agents, and antifungal shampoos.
      • Kwak H.B.
      • Yun S.K.
      • Kim H.U.
      • Park J.
      Pityriasis amiantacea: an epidemiologic study of 44 cases in Korean patients.
      Pityriasis amiantacea should be included in the differential diagnosis of a scaly scalp rash and considered for associated conditions.

      Potential Competing Interests

      Dr Xie has won the Geoffrey Dowling Fellowship from the British Association of Dermatologists and received the Appignani Lichen Planus Benefactor Gift. The other author reports no competing interests.

      Acknowledgments

      We are grateful to the Appignani Lichen Planus Benefactor Gift and the British Association of Dermatologists ’ Geoffrey Dowling Fellowship for supporting Dr Xie’s visiting research fellowship.

      References

        • Knight A.G.
        Pityriasis amiantacea: a clinical and histopathological investigation.
        Clin Exp Dermatol. 1977; 2: 137-143https://doi.org/10.1111/j.1365-2230.1977.tb01557.x
        • Kwak H.B.
        • Yun S.K.
        • Kim H.U.
        • Park J.
        Pityriasis amiantacea: an epidemiologic study of 44 cases in Korean patients.
        Ann Dermatol. 2020; 32: 83-87https://doi.org/10.5021/ad.2020.32.1.83
        • Ettler J.
        • Wetter D.A.
        • Pittelkow M.R.
        Pityriasis amiantacea: a distinctive presentation of psoriasis associated with tumour necrosis factor-α inhibitor therapy.
        Clin Exp Dermatol. 2012; 37: 639-641https://doi.org/10.1111/j.1365-2230.2011.04286.x
        • Abdel-Hamid I.A.
        • Agha S.A.
        • Moustafa Y.M.
        • El-Labban A.M.
        Pityriasis amiantacea: a clinical and etiopathologic study of 85 patients.
        Int J Dermatol. 2003; 42: 260-264https://doi.org/10.1046/j.1365-4362.2003.01755.x
        • Verardino G.C.
        • Azulay-Abulafia L.
        • de Macedo P.M.
        • Jeunon T.
        Pityriasis amiantacea: clinical-dermatoscopic features and microscopy of hair tufts.
        An Bras Dermatol. 2012; 87: 142-145https://doi.org/10.1590/s0365-05962012000100021