Cutaneous mastocytosis

Generic term for clinically heterogeneous clinical pictures characterized by mast cell hyperplasia in the skin (and in internal organs). The spectrum ranges from solitary skin tumors to variously pronounced (variants of the so-called"urticaria pigmentosa"), in extreme cases erythrodermic skin manifestations.

The term "cutaneous mastocytosis" implies a purely cutaneous clinical picture. This is mostly found in children, less frequently in adults. Adult forms of mastocytosis are usually a "systemic disease" with a differently accentuated extracutaneous pattern of infestation, in which the cutaneous infestation can be regarded as a monitory and thus frequently leading to a diagnosis.

Tryptase: If systemic mastocytosis is suspected, tryptase is determined according to the guidelines (standard value: <20µg/l). If the value is exceeded, systemic mastocytosis is considered possible and a bone marrow biopsy and screening for other systemic involvement is sought. At low levels, extensive diagnostic testing is usually not performed without compelling clinical evidence. In a larger study, systemic mastocytosis could be confirmed in 32% of patients with cutaneous mastocytosis by bone marrow histology. In addition, N-methylhistamine or 1,4-methylimidazole acetic acid can be determined in the collected urine.

Depending on the clinic, the following forms are distinguished among the cuntanous mastocytoses (classification of mastocytoses, modified according to Golkar)

mastocytoma(s)

• cutaneous mastocytoma
• Multiple cutaneous mastocytomas

Diffuse cutaneous mastocytosis

Adult cutaneous mastocytosis (maculopapular CM = MPCM)

• Maculopapular cutaneous mastocytosis (classic type = MPCM)
• Teleangiectasia macularis eruptiva perstans

Cutaneous mastocytosis of childhood

• Maculopapular cutaneous mastocytosis (Urticaria pigmentosa) (classic type = MPCM)
• Teleangiectasia macularis eruptiva perstans (extremely rare in childhood)

Special forms (old nomenclature)

• Urticaria pigmentosa haemorrhagica
• Exanthematic urticaria pigmentosa
• Urticaria pigmentosa bullosa
• Urticaria pigmentosa xanthelasmoidea

1. Di Raimondo C et al (2021) Cutaneous mastocytosis: A dermatological perspective. Australas J Dermatol 62:e1-e7.
2. Fox WT (1875) On xanthelasmoidea (an undescribed eruption). Trans Clin Soc London 8: 53
3. Frieri M et al (2013) Pediatric mastocytosis: A review of the literature. Pediatr Allergy Immunol Pulmonol 26:175-180.
4. Golkar L, Bernard JD (1997) Mastocytosis. Lancet 349: 1379-1385
5. Méni C et al (2015) Paediatric mastocytosis: a systematic review of 1747 cases. Br J Dermatol 172:642-651
6. Sukesh MS et al (2014) Solitary mastocytoma treated successfully with topical tacrolimus. F1000Res 3:181