SAPHO osteomyelitis and sarcoid dermatitis in a patient with DiGeorge syndrome

We report the development and spontaneous resolution of annular erythematous skin lesions consistent with sarcoid dermatitis in a child with DiGeorge syndrome (DGS) carrying the 22q11.2 microdeletion. The skin lesion developed after she was treated with isoniazid (INH) following exposure to active tuberculosis (TB). After resolution of the skin lesions, this child developed sterile hyperplastic osteomyelitis consistent with SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) osteomyelitis in her right mandible triggered by an odontogenic infection. This child had congenital heart disease, dysmorphic facies, recurrent sinopulmonary infection, gastroesophageal reflux disease, scoliosis, reactive periostitis, and developmental delay. She had a low CD4 and CD8 T cell count with a normal 4/8 ratio, but normal cell proliferation and T cell cytokine production in response to mitogens. When she was presented with sterile osteomyelitis of right mandible, she revealed polyclonal hypergammaglobulinemia with elevated erythrocyte sedimentation rate (ESR)/angiotensin converting enzyme (ACE) levels, but negative CRP. Autoimmune and sarcoidosis workup was negative. Inflammatory parameters gradually normalized following resolution of odontogenic infection and with the use of non-steroidal anti-inflammatory drugs (NSAIDs). The broad clinical spectrum of DGS is further expanded with the development of autoimmune and inflammatory complications later in life. This case suggests that patients with the DGS can present with unusual sterile inflammatory lesions triggered by environmental factors, further broadening the clinical spectrum of this syndrome.