Mastocytosis in the skin (MIS) demonstrates heterogeneity among children and adults, with different types of cutaneous mastocytosis (CM) lesions noted in each patient population, according to the results of a retrospective, observational study published in the Swedish journal Acta Dermato-Venereologica.

The World Health Organization divides mastocytosis into 2 main categories: systemic mastocytosis (SM) and CM. Recognizing that cutaneous lesions in individuals with mastocytosis are highly heterogeneous in nature, the researchers sought to describe the differences in cutaneous involvement in adults and children from Greece with MIS.

Adult-onset MIS almost always persists throughout an individual’s life and is usually associated with SM. In contrast, childhood-onset MIS presents with spontaneous resolution around the time of puberty, with most pediatric patients presenting with no evidence of histologic involvement of other organs.

The current study, conducted between 2009 and 2022, included patients with MIS from 2 different institutions in Greece: (1) the Mastocytosis & Mast Cell Activation Disorders Allergy Unit “D Kalogeromitros” of Attikon University General Hospital of Athens and (2) the Allergy Department, 2nd Pediatric Clinic of the University of Athens at Panagiotis & Aglaia Kyriakou Children’s Hospital.

All participants were divided into 2 groups according to their age at MIS diagnosis: less than 16 years (ie, children) and 16 or more years (ie, adults). The adult participants were further divided into 2 subgroups based on their reported age at disease onset: less than 16 years (childhood-onset MIS) and 16 or more years (adult-onset MIS).

A total of 108 individuals with MIS were enrolled in the study. Among the participants, 46 were children (mean age, 2.2 years; range, 0-10 years) and 62 were adults (mean age, 37.9 years; range, 16-66 years) at the time of diagnosis. The prevalence of MIS was similar in males (47%) and females (53%); however, a slight predominance of males (62.2%) was observed among children, whereas in adults, females (62.9%) were diagnosed with MIS more often than males (P =.022),

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Overall, 30.6% (33 of 108) of the patients were diagnosed with SM, 48.1% (52 of 108) of them with CM, and 21.3% (23 of 108) with MIS. Of the 33 individuals with SM, 32 were adults and 1 was a child. The majority of adults (90.3%) presented with onset of skin involvement in adulthood, with childhood onset of skin involvement reported in only 9.7% of participants.

Among the children, 67.4% (31 of 46) of them presented with polymorphic maculopapular cutaneous mastocytosis (MPCM), 13.0% (6 of 46) of them exhibited monomorphic MPCM, and 19.6% (9 of 46) of them had solitary mastocytoma. In all children except 1, the initial lesions presented during the first 2 years of life.   

Data on the type of cutaneous lesions were available for only 38 of the 62 adults. Overall, 97.4% (37 of 38) of them presented with monomorphic MPCM and 2.6% (1 of 38) of them presented with atypical skin involvement (ie, mast cell infiltrates on skin biopsy).

The authors concluded, “[T]his study demonstrates the different types of CM lesions in children and adults[, as well as] different extracutaneous involvement, which suggest[s] that MIS should be approached differently based on age.”

Reference

Fokoloros C, Xepapadaki P, Papadavid E, et al. Mastocytosis in the skin: disease heterogeneity among children and adults. Acta Derm Venerol. 2023;103:aadv00845. doi:10.2340/actadv.v103.4461