Dermatology Facts

Dermatology Facts—Mastocytosis

This is a condition in which there are accumulations of white blood cells called mast cells in the skin and sometimes in other organs.

In the skin, these accumulations appear as brown patches or subtle lumps. The mast cells contain histamine; a chemical which when activated may cause an itchy red spot, a hive or even a blister. This reaction is similar to the reaction from a mosquito bite or bee sting.

These reactions occur when the histamine is released from the mast cells. This can occur when the spots are rubbed, when the patient is exposed to heat or as a result of ingestion of a variety of drugs. Where possible these drugs should be avoided in patients with multiple spots of mastocytosis. Any doctor who is going to prescribe a drug to the child should be given a list of the drugs which may cause histamine release. In most cases a dangerous reaction does not occur, but there may be a redness and swelling of the spots and a generalized flushing. Very rarely, a drop in blood pressure may accompany severe flushing.

In most patients with mastocytosis, the spots disappear in 5-10 years. For most children with one or a few spots, the condition is not serious at all. At worst it is a nuisance if the spots become stimulated and they become itchy, red or blister. In a few patients, they can lead to significant flushing which can usually be controlled by antihistamines. Patients with more severe disease can potentially be at greater risk of generalized flushing, diarrhea or drop in blood pressure. If your child has any of these symptoms, they should be reported to your physician immediately.

Agents which may cause flushing in patients with Mastocytosis

  • Bee Stings
  • Dextromethorphan
  • Morphine
  • Codeine (note: some cough mixtures contain codeine)
  • Aspirin
  • Atropine, pilocarpine, some general anesthetics
  • Quinine
  • Procaine
  • X-ray contrast media
  • Alcohol (found in some over the counter cold/cough products)
  • Various shellfish
  • Topical antibiotics
  • Physical stimuli (heat, cold, friction)
  • Snake venom, jelly fish stings