What is the most likely diagnosis for a patient experiencing severe, unilateral headaches accompanied by nasal congestion and tearing?

• A. Alcohol-induced vasodilation
• B. Allergic rhinitis
• C. Cluster headache
• D. Temporal arteritis

Answer: (C)

The symptoms described—severe, unilateral headaches along with nasal congestion and tearing—are characteristic of a cluster headache. Cluster headaches are known for their sudden onset and can be extremely painful, often described as a burning or piercing sensation. They typically occur in clusters, leading to a pattern of episodes that can happen at the same time every day over a period of weeks or months, followed by remission.

The accompanying symptoms of nasal congestion and tearing are particularly notable, as they can occur due to the involvement of the trigeminal nerve during a cluster headache attack. This can lead to autonomic symptoms such as lacrimation (tearing) and rhinorrhea (runny nose), which further aligns with the presentation of cluster headaches.

While the other conditions listed may involve headaches or nasal symptoms, they do not match the specific combination and intensity of symptoms associated with cluster headaches. For example, allergic rhinitis primarily leads to nasal symptoms and does not usually cause severe unilateral headaches. Alcohol-induced vasodilation could potentially trigger headaches but wouldn't typically present with nasal congestion and tearing. Temporal arteritis would more often present with a different type of headache, possibly with more systemic features, such as jaw claudication or vision changes, rather than the acute, sudden onset