Headaches in a rheumatology clinic: when one pain leads to another

Chronic daily headaches (CDH) affect between 3 and 4% of the Western population and is one of the most common problems seen in the neurology clinic. It is often difficult to delineate where CDH began and medication overuse headache (MOH) supervenes. The current study analyses the development of MOH in people taking regular analgesia for reasons other than headache, namely patients attending rheumatology clinics. The aim of this study was to assess, for the first time in an Irish population of patients, whether CDH was more common in such patients as previously reported. We also wanted to see how often rheumatology patients were taking non-prescribed analgesics. The results show that, in a cohort of 114 rheumatology patients, 32% reported that they suffer from headaches regularly. Of these, 38% fulfilled criteria for CDH (or 12% of the whole cohort). Of the 14 patients with CDH, 11 also fulfilled the International Classification of Headache Disorders criteria for MOH. Seventy per cent of the patients fell under the category of medication overuse (> 15 days a month for > 3months) but only 9% fulfil criteria for MOH. Contrary to the previous work in this area, we found a very low (< 2%) incidence of previous migraine in our patients with CDH. We conclude that headaches (both CDH and MOH) are common in this patient population. We suggest that here should be greater awareness amongst all doctors caring for these patients of the potential for creating a second chronic problem when using excessive analgesia to treat the first.