Tehran University of Medical Sciences Immunology and Genetics Journal 2645-4831 4 2 2021 06 22 119 123 Mohammad Nabavi Department of Allergy and Clinical Immunology, Rasool e Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Saba Arshi Department of Allergy and Clinical Immunology, Rasool e Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Mohammad Hasan Bemanian Department of Allergy and Clinical Immunology, Rasool e Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Morteza Fallahpour Department of Allergy and Clinical Immunology, Rasool e Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Vahid Bakrani Department of Allergy and Clinical Immunology, Rasool e Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Sima Shokri Department of Allergy and Clinical Immunology, Rasool e Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. 2022 01 23 2022 04 04 X-Linked Agammaglobulinemia (XLA) is a prototype of humoral immunodeficiency disorders manifested by recurrent sinopulmonary infections and characterized with low to absence of immunoglobulin production due to absence of B lymphocytes. There are many reports of unusual complications of this genetic disease such as Pneumocystis carinii pneumonia, enteroviral infections with diverse manifestations, neutropenia during severe infections and also uncommon reports of some autoimmunities. Moreover, Rheumatological diseases are reported as a manifestation of XLA among which dermatomyositis is a known and expected condition. Other connective tissue diseases are rarely reported. In this report, the researchers described a known case of XLA disease with progressive body pain, muscle ache, tender and tense skinand finally confirmed as a rare occurrence of Eosinophilic Fasciitis / Morphea Overlap. https://igj.tums.ac.ir/index.php/igj/article/view/90 https://igj.tums.ac.ir/index.php/igj/article/download/90/75