Case Studies

 Case 4.5 Perennial allergic rhinitis

A 29-year-old doctor developed intense itching of her eyes and nose and a tickling sensation in her ears and palate, followed by sneezing and rhinorrhoea. These symptoms developed within 15min of visiting an elderly patient who kept four cats. The symptoms settled down over the next 2h but started to recur whenever home visits were made to houses where cats were present. Symptoms occurred even though the cats were excluded from the interview room. Each episode took slightly longer to resolve and some were accompanied by a dry cough.

The doctor had suffered from asthma in childhood and her non-atopic parents had a cat. During her years in medical school and in hospital posts, she had no respiratory symptoms. The move into general practice and exposure to cat dander had triggered perennial allergic rhinitis. On investigation, she had strongly positive skin tests to cat dander, house dust mite and grass pollen. Perennial allergic rhinitis - Skin testing with dilutions of grass pollen showed white raised areas with surrounding oedema, known as "wheat & flare", after 20 minutes. Also red and more "infiltrated" areas after 5 hours (due to the late reaction). She started prophylactic use of a nasal spray and eye drops containing sodium cromoglycate, with abolition of most of her symptoms. Sometimes, she also needed to use a local antihistamine spray to relieve breakthrough attacks of rhinitis. The value of hyposensitization (antigen-specific immunotherapy) to cat dander was discussed because occupational exposure was unavoidable but not undertaken while her symptoms continued to be controllable.