Horse dander a cause of asthma in children

Bashkir Curly horses have very short curly hair and appear to give off very little dander
making them excellent for potentially allergic children.

An article in the BMJ (BMJ. 2000 July 29; 321(7256): 286–287) by Graham Roberts and Gideon Lack at St Mary’s Hospital in London used three cases (of 28 seen recently) to illustrate that horse dander can be a significant cause of a child’s asthma even in an urban environment.

An eight year old boy started to wheeze and had to be treated in A & E immediately after riding a pony at a fête; tests revealed allergy to both horse dander and house dust mite

A nine year old boy with badly controlled asthma was found to be reacting to his sister’s riding clothes which were kept in their shared bedroom and improved dramatically once she stopped riding.
A five year old boy, on two successive summers, had required treatment in the A & E department for wheeze and sneezing, which developed while walking through fields. On the first occasion he had been eating an ice cream with nuts so the reaction was attributed to either nut allergy or hay fever but skin prick testing, produced no reaction to nuts and only a small weal to grass pollen. Closer questioning showed that on both occasions he had come into close contact with a horse. Skin prick testing to horse dander produced a 12 mm weal.                 
Household pets are well known to cause allergic asthma. A history of past pet ownership, especially cats, has been found to be related to an increased rate of pet allergy and asthma. Much less is known about horse allergy and given that today there are few horses in towns and allergic sensitisation requires chronic or regular exposure to allergen one might expect horse allergy to be a rare problem in urban environments. However, this does not appear to be the case.

Horse dander may represent a “hidden” allergen because exposure either is indirect or does not immediately precede the development of symptoms. Moreover, horse allergen seems to be as tenacious as cat allergen, enabling it to be transferred on clothing and brought into a house far from the horse itself.

Avoidance of allergens is critical in the management allergy and may be sufficient to control symptoms but although it is simple to avoid direct exposure to horses, avoiding indirect exposure can be more difficult.
Even in urban populations horse allergy can cause a wide range of symptoms from urticaria to respiratory distress, with both early and late phase respiratory symptoms. Successful avoidance may dramatically improve the control of childhood asthma and reduce the need for steroids.

For the full report

First Published in 2000

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