Silk-induced asthma in children: a report of 64 cases.
 A total of 64 children less than 15 years of age with asthma caused by silk were studied.
 The diagnosis was based on a history of wheezing, positive skin tests to silk, positive conjunctival or nasal provocation tests, or serum IgE-Sw (silk waste).
 The average age of onset was 4 years 2 months.
 Sex ratio (M:F) was 3.6:1.
 A positive skin test is essential for the diagnosis.
 Conjunctival provocation tests were performed in 80% of cases because of reliability, safety, and convenience.
 The first symptom appeared an average of 10 months after initial exposure to silk.
 In 61% of patients, asthma was accompanied by allergic rhinitis but in only 14% of cases by conjunctivitis.
 In most cases, asthma occurred in winter, due to seasonal use of bed quilts or clothes filled with silk.
 Silk is a highly potent allergen.
 The average mean wheal diameter elicited by silk in prick testing was larger than two histamine equivalent prick tests.
 A cross reactivity exists among mulberry silk, and silkworm cocoons, batryticated silkworms, and silkworm chrysalis.
