Researchers presented a case of alopecia in a patient with cutaneous manifestations of systemic mastocytosis in Annals of Clinical Case Reports. 

A 12-year-old boy had a history of alopecia on his scalp and body for the previous 9 years. The lesions were described as being reddish-brown in color and itchy. 

Upon physical examination, the patient was found to have a positive Darier’s sign. Further investigations did not reveal the involvement of any other organs. However, a pathology report with a fragment of skin tissue indicated that it was 0.3 × 0.2 cm thick with an unremarkable epidermis. 

The underlying dermis demonstrated mild interstitial edema with a mild infiltrate of lymphocytic inflammatory cells; these were admixed with eosinophils around small capillaries with prominent endothelial cells, mostly seen in the superficial and mid-dermis. The pathology report also revealed metachromatic granules in methylene blue stain, which is indicative of dermis spindle cell proliferation. 

Read more about systemic mastocytosis etiology

Based on these findings, the boy’s physicians chose to conduct a skin biopsy, which revealed a diagnosis of cutaneous mastocytosis.

“Scarring alopecia with increased mast cell numbers on scalp biopsy justifies the diagnosis of mastocytosis,” the authors wrote. 

The patient was then placed under frequent monitoring and received supportive care, bringing the symptoms of his cutaneous mastocytosis under control. 

Nevertheless, 6 months prior, the patient experienced increased itching in the scalp area. A physical examination revealed what appeared to be a scaly macule. Subsequent visits revealed irregular and asymmetric areas of alopecia in the scalp area. 

Cutaneous mastocytosis primarily affects the skin. Medical literature recognizes 3 main forms of this disease: maculopapular cutaneous mastocytosis, solitary cutaneous mastocytoma, and diffuse cutaneous mastocytosis. Symptoms and severity of the condition can vary according to subtype. Studies indicate that mast cell granules may play a role in regulating the development and cycling of hair follicles, thereby causing alopecia in some patients with this disorder. 


Bemanian MH, Asefi S, Nabavi M, et al. A case report of alopecia in a patient with cutaneous mastocytosis. Ann Clin Case Rep. Published online April 15, 2023.