BACKGROUND
H syndrome is an autosomal recessive disorder of histiocytic proliferation with clinical spectrum of unique cutaneous and systemic manifestations. There is no consistent treatment for the disease, and all available options are based on case reports. Here, we present the chronological progression of a case of H syndrome with typical cutaneous manifestations that was misdiagnosed early as meningitis-induced sensorineural hearing loss and later as a non-defined autoimmune connective tissue disease. A new tried, although failed, treatment option is described as well.
CASE REPORT
A 31-year-old Saudi woman born of a consanguineous marriage presented to our dermatology clinic with symmetrical indurated hyperpigmented to violaceous plaques over the medial thighs, upper legs, lower back, volar wrists, and upper arms, associated with hypertrichosis. Hallux valgus of the big toes was clinically detected as well. She had a history of sensorineural deafness, diabetes mellitus, chronic anemia, and hypothyroidism. Genetic analysis of the patient showed a homozygous frameshift pathogenic variant of the SLC29A3 gene, c.243del p.(Lys81Asnfs*20). Systemic treatments in the form of methotrexate and imatinib had been tried; however, both failed to control her sclerotic cutaneous changes.
CONCLUSIONS
Knowing the early life presentation and the variable clinical symptoms of H syndrome is crucial in early intervention and further prevention of the non-reversible changes. Moreover, avoiding unnecessary immunosuppressive medication use is warranted in certain circumstances.

Keywords: Histiocytosis; Imatinib Mesylate; Histiocytosis with Joint Contractures and Sensorineural Deafness; SLC29A3 Protein, Human