AHMF: 98 Conference: Reeves

Profile of Chronic Fatigue in an Immunology Clinic

Glenn Reeves [1], Robert Clancy [2].

1 Hunter Immunology Unit
Hunter Area Pathology Service
Royal Newcastle Hospital
2 Faculty of Medicine and Health Science
University of Newcastle.

In recent years, a significant proportion of referrals to clinical immunology clinics have presented with the diagnosis of "chronic fatigue syndrome", despite the fact that neither the aetiology nor the pathogenesis of this heterogeneous syndrome has an identified immunological basis. In this retrospective study of 184 consecutive subjects referred with unexplained fatigue of six or more months duration, we set out to provide a more structured framework for the assessment and management of patients with chronic fatigue.

The 184 patients fell into 5 categories: CFS (59%), Organic Disease (18%), Primary Psychiatric Disorder (14%) Fibromyalgia (5%), and Primary Sleep Disorder (2%). 2% of patients were unclassified. The mean duration of symptoms for all patients and CFS patients were 57.1 and 54.4 months respectively. A history of cognitive impairment was found significantly more often in CFS and Psychiatric Disorder patients than in other groups. A history of acute symptom onset was found significantly more often in CFS and Organic Illness than in other groups. Immunoglobulins, T cell subsets and EBV serology did not differentiate between diagnostic groups.

In distinguishing between the two major groups, CFS and Organic Illness, the combination of haemoglobin SR, ANA and TSH was a powerful discriminator.

While there is little doubt that CFS is a real syndrome, it was clear from our study that CFS has become diagnosis often accepted uncritically by both doctor and patient, with 39% of patients referred to this Unit having an alternative diagnosis. The consequence of misdiagnosing CFS in these cases was frustration, multiple referrals, absence of a management plan and delayed diagnosis of often treatable conditions.

Immunological investigations (other than antinuclear antibody) were of no diagnostic benefit.

In conclusion, a significant proportion of patients referred to our Unit with a provisional diagnosis of CFS were found to have other underlying treatable conditions. A thorough clinical history and examination, as well as the judicious use of a limited number of investigations (FBC, ESR, ANA and TSH) is vital in approaching the patients with unexplained chronic fatigue.