Table 1 Classification of SUNA according to the second edition of the International Classification of Headache Disorders

A At least 20 attacks fulfilling criteria B–E

B Attacks of unilateral orbital, supraorbital or temporal stabbing or pulsating pain lasting from 2 s to 10 min

C Pain is accompanied by one of

 1. Conjunctival injection and/or lacrimation

 2. Nasal congestion and/or rhinorrhea

 3. Eyelid oedema

D Attacks occur with a frequency of ≥1 per day from more than half of the time

E No refractory period follows attacks triggered from trigger areas

F Not attributed to another disorder