Congenital mastocytosis

Pediatric mastocytosis occurs before the age of 2 years in 90% of cases and is often limited to the skin. PM is congenital in 15-31% of patients. We retrospectively evaluated the features of mastocytosis present at birth in human-subject studies published in PubMed databases between 1917 and 2016, except for those lacking many epidemiologic and follow-up data. We collected data about 45 patients (32 males and 13 females): 27 diffuse cutaneous mastocytosis (DCM), 14 urticaria pigmentosa (UP), 2 solitary mastocytoma and 2 teleangectasia macularis eruptive perstans (TMEP). Extracutaneous involvement was reported in 70.37% of DCM and in 57.14% of UP: the most common were hepato(spleno)megaly or mast cell liver infiltration in DCM and gastrointestinal symptoms in UP. A higher prevalence of DCM in males was reported. DCM is often associated with extracutaneous involvement and, in some cases, with aggressive systemic mastoctytosis or early death. A myeloproliferative disorder may appear concomi tantly or after the improvement of cutaneous manifestations. Regression (partial or total) occurred in 51.11% of all patients. Data about long term prognosis are few because only some cases were monitored after puberty. Spontaneous regression before or at puberty is common in early onset mastocytosis but does not always occur. Reliable prognostic clues are lacking in infants, therefore careful long-term follow-up is essential for the early detection of systemic involvement