system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
H1 antihistaminics afford benefit in a number of conditions. All of the following conditions are benefited by antagonism of histamine :
assistant
The correct answer is  In common cold , excessive secretions (like rhinorrhoea) are due to cholinergic overactivity. First generation antihistaminics possess anticholinergic propey and therefore are effective for common cold. On the other hand, all other conditions are allergic and reare benefited by antagonism of H1 receptors.