Commentary: Condition is often overlookedBMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b799 (Published 09 March 2009) Cite this as: BMJ 2009;338:b799
- Gerhard J Molderings, associate professor of pharmacology and toxicology
This report of hypotensive shock as the initial sign of systemic mastocytosis brings attention to an important but underestimated disease. Although systemic mast cell activation syndrome, a variant form of systemic mastocytosis, is probably common in daily practice (for example, it seems to be linked to certain forms of irritable bowel syndrome1), this differential diagnosis is seldom considered. As in the present case, systemic mastocytosis often first presents as an emergency, mostly as a gastrointestinal emergency,2 but bleeding and neurological emergencies have also been reported.
Systemic mastocytosis is primarily a clinical diagnosis. The diagnosis relies first and foremost on the recognition of the complex variable and often changing pattern of symptoms (such as pruritus, flushing, tachycardia, palpitations, light headedness, dizziness, shortness of breath, nausea, diarrhoea, or headache). The pattern depends on the tissue responses to mediators released from mast cells and on the burden of mast cells in local tissue. The syndrome can be identified by validated questionnaires.3 The more characteristic the clinical findings are of pathological systemic mast cell activation, the less importance must be attached to laboratory biomarkers such as serum tryptase level, which have only limited reliability. In this context it is important to note that the so called consensus (or World Health Organization) criteria for systemic mastocytosis do not give a definite conclusion.4 The criteria provide a provisional, state of the art description that predominantly considers one variant form of systemic mastocytosis (that associated with the mutation of the tyrosine kinase Kit gene at codon 816).
Treatment of the disorder consists of avoiding triggers when possible, together with antihistamines and drugs that stabilise mast cell membranes such as sodium cromoglycate. The basic treatment can be supplemented, if required, with drugs targeting individual symptoms.
Cite this as: BMJ 2009;338:b799
Competing interests: GJM has had a research project funded by Novartis UK.