Therapeutic challenge during the long-term follow-up of a patient with indolent systemic mastocytosis with extensive cutaneous involvement.

From a dermatological aspect, it posed a considerable challenge the skin-limited form of mastocytosis, urticaria pigmentosa and indolent systemic mastocytosis (ISM) with cutaneous lesions. Despite the favourable prognosis, lifelong dermatological control is needed, during which the average symptomatic therapy does not always seem adequate. We report here the case of a female ISM patient with recurrent cutaneous symptoms that impaired her quality of life, with a follow-up time of 27 years. During this long follow-up period, the cutaneous lesions could be controlled by antihistamines, leukotriene antagonists, glucocorticoids, local immunosuppressants or local UV radiation for only relatively short periods. Imatinib mesylate was, therefore, introduced in an attempt to control the cutaneous lesions. Tyrosine kinase inhibition is an unusual dermatological therapeutic option. This case illustrates that imatinib mesylate was a good choice with which to achieve a reduction of the skin lesions in this KIT D816V mutation-negative disease: it led to a temporary appreciable improvement of the patient's quality of life.