Cholinergic nervous system and immediate hypersensitivity: II. An analysis of pupillary responses

We studied the pupillary responses of various subjects to carbamylcholine chloride (CCC) in order to assess cholinergic responsiveness. Using the concentration of topical CCC required to induce ≧1 mm miosis in the dark as the end point, we compared the responses of five groups of subjects: normal controls; patients with allergic asthma, allergic rhinitis, or intrinsic asthma; and a group who had reproducibly positive skin tests in the absence of symptoms. Subjects with allergic rhinitis or allergic asthma were significantly more sensitive than were normal controls. The patients with positive skin test and negative history were as sensitive as their symptomatic cohorts, suggesting that pupillary cholinergic hyperresponsiveness exists in atopic individuals regardless of symptoms. A small group with intrinsic asthma was examined and found to be even more sensitive than any of the atopic subjects. Thus abnormal hyperresponsiveness of the pupillary constrictor muscles to a topically instilled cholinomimetic has been found in all groups of atopic subjects plus nonallergic asthmatics. Analysis of pupillary responses may prove useful in assessment of autonomic responsiveness.