1. Histamine, both free and cell associated, has been demonstrated in middle ear fluid from patients with secretory otitis media (SOM).
2. Histamine, mainly free in solution, has also been shown to be present in nasopharyngeal secretions taken from close to the Eustachian tube openings into the nasopharynx.
3. The adenoids from patients with middle ear effusion contained significantly (P<0.05) more histamine than those with no effusion.
4. However, in preliminary experiments, we could demonstrate no differences in the histamine secretory response of adenoids from SOM and non-SOM patients to anti-immunoglobulin E (anti-IgE), house dust mite antigen and calcium ionophore A23187 in vitro.
5. These results support the hypothesis of an inflammatory basis for SOM.