Diffuse Cutaneous Mastocytosis: A Current Understanding of a Rare Disease

Abstract

Mastocytosis is a heterogeneous disease characterized by the expansion and accumulation of neoplastic mast cells in various tissues. Diffuse cutaneous mastocytosis (DCM) is a rare and most severe form of cutaneous mastocytosis, which typically occurs in childhood. There have been reports of a familial DCM with specific gene mutations, indicating both sporadic and hereditary factors involved in its pathogenesis. DCM is associated with severe MC mediator-related symptoms and an increased risk of anaphylaxis. The diagnosis is based on the appearance of skin lesions, which typically show generalized thickening, erythroderma, blistering dermographism, and a positive Darier's sign. Recognition, particularly in infants, is challenging due to DCMs resemblance to other bullous skin disorders. Therefore, in unclear cases, a skin biopsy is crucial. Treatment focuses on symptom management, mainly including antihistamines and mast cell stabilizers. In extremely severe cases, systemic steroids, tyrosine kinase inhibitors, phototherapy, or omalizumab may be considered. Patients should be equipped with an adrenaline autoinjector. Herein, we conducted a comprehensive review of literature data on DCM since 1962, which could help to better understand both the management and prognosis of DCM, which depends on the severity of skin lesions, intensity of mediator-related symptoms, presence of anaphylaxis, and treatment response.

Keywords: diagnosis; diffuse cutaneous mastocytosis; pediatric mastocytosis; treatment; tryptase.

Figure 1

DCM with extensive blistering in an infant.

Figure 2

Skin biopsy from a patient with DCM showing a marked infiltrate of round to polygonal MCs occupying the whole papillary dermis ((A), H&E stain ×4; (B), H&E stain ×20; (C), CD117 stain ×4; (D), CD117 stain ×20)).