Management of Adult-Onset Cutaneous Mastocytosis: A Case Report

Introduction Mastocytosis – is a rare disorder characterized by excessive proliferation and accumulation of abnormal mast cells in tissues. It can present as cutaneous mastocytosis (CM), involving only the skin, or as systemic mastocytosis (SM), affecting extracutaneous tissues [1]. Affecting 1 in 10,000 people, adult-onset CM is rare and often indicates systemic involvement, comprising less than 5% of adult cases [2–3]. Case Presentation A 67-year-old female with a two-year history of confirmed CM presented with an exacerbation characterised by facial flushing, eye irritation/redness, pruritic rash on extremities and torso, as well as joint pain. The patient was currently taking Cetirizine 10 mg q.d. for the treatment of CM. Previous therapies included topical corticosteroids, calcineurin inhibitors, antihistamines, PUVA and UVB. There was no evidence of SM found during previous hospitalisations. Last known serum tryptase level – 22 ng/mL. Due to the disease's widespread nature, the patient was hospitalized in the Department of Skin and Venereal Diseases. Examination revealed pink and brownish-blue nodules and papules with erythema on the chest, trunk, forearms, and thighs, and a positive Darier's sign. The face was erythematous with visible telangiectasias. Local treatment with Loratidine 10 mg b.i.d., Dexamethasone 0.005% cream b.i.d. and PUVA phototherapy baths (N4) with a cumulative dose of 1.6 J/cm² were applied, resulting in improved skin condition. The patient was re-evaluated for SM; the haematologist determined that no further tests were needed, the rheumatologist found no autoimmune joint disease, and the abdominal ultrasound showed no SM-related abnormalities. After completing the treatment plan, the patient was discharged for further outpatient care. Discussion No large randomized controlled trials have evaluated therapies for CM; current treatment recommendations rely on data from small case series and expert opinion [4]. CM management is symptom-focused, with antihistamines, topical corticosteroids, and phototherapy being effective options [5]. Conclusions This case highlights the importance of an interdisciplinary team in treating adult-onset CM. Although this form of mastocytosis typically has a benign prognosis, continuing monitoring of disease progression and symptom management are crucial.