D. Vangysel et al., VALUE OF URINARY N-METHYLHISTAMINE MEASUREMENTS IN CHILDHOOD MASTOCYTOSIS, Journal of the American Academy of Dermatology, 35(4), 1996, pp. 556-558
Background: Histamine is an indicator of mast cell activation. N-methy
lhistamine (NMH) is a metabolite of histamine that can he measured in
urine. Objective: Our purpose was to assess the usefulness of determin
ing urinary NMH levels for the diagnosis and follow-up of patients wit
h mastocytosis. Methods: Urinary NMH levels were determined in 44 pati
ents and were correlated with disease activity and extension. The cont
rol group consisted of 24 children without mastocytosis or any other s
kin disease. Results: A significant negative correlation was found bet
ween NMH and age in patients with active mastocytosis and in the contr
ol group. Adjusted for age, NMH values were significantly higher in pa
tients with active mastocytosis. There was a significant difference in
NMH values between patients with diffuse cutaneous mastocytosis, pati
ents with active urticaria pigmentosa, and patients with active mastoc
ytomas. However, there was a substantial overlap of NMH values in the
different subgroups. Conclusion: Urinary NMH values tend to decrease w
ith age. Urinary NMH values correlated with the extent and the activit
y of the disease. High NMH values suggest more extensive involvement.