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
Periodicity is a characteritic featurw in which sinus infection:
assistant
The correct answer is  Pain of frontal sinusitis shows characteristic periodicity,i.e comes upon walking,gradually increases and reaches its peak by midday and then stas subsiding. It is also called office headache as it is present only during office hours. Ref Dhingra 6/e p 192