<unk>  does not have a confirmed cause, being a primary headache, but can be identified with other primary conditions. "As many as 40% of all individuals with ice pick headaches have also been diagnosed as suffering with some form of migraine headache."
Ophthalmodynia periodica
Oculomucocutaneous syndrome
Floppy eyelid syndrome
Oculoauricular syndrome
Rectovestibular fistula
Vulvar vestibulitis
Nasal vestibulitis
Vestibular adenitis