Histamine skin sensitivity in chronic schizophrenic smokers not responding favourably to neuroleptics

Histamine, the neurotransmitter involved in both immune and allergic responses to stress, has been reported to affect acute and chronic schizophrenic patients differently in histamine skin sensitivity tests. The authors tested for histamine skin sensitivity patients who had been hospitalized with diagnosed schizophrenia for many years who had not responded favourably to conventional therapy and who had been consistently exposed to active and/or passive smoking. These patients were found to be markedly sensitive to the histamine skin test, whereas a control group of non-hospitalized, non-smoking, non-allergic, non-medicated, 'healthy' volunteers, of similar age and sex, were not sensitive to the histamine intracutaneous test. These findings suggest a possible screening indicator in respect of which patients with a diagnosis of schizophrenia will respond favourably or not favourably to neuroleptics.