Fever of unknown origin in an elderly man

Journal of Family Practice, Sept, 1990 by Navin Amin, William A. Norcross, Sidney L. Saltzstein

There are a number of other infectious diseases that must be kept in mind. Brucellosis is one example. In the last year, we have diagnosed three cases of brucellosis at the Kern Medical Center. Similarly, listeriosis, and particularly Listeria endocarditis, can be a very baffling disease. Syphilis, particularly in the secondary and tertiary phases, may present with longstanding pyrexia. Rickettsial diseases must also be considered. At the Kern Medical Center, we have diagnosed quite a number of cases of Q-fever because this disease is commonly found among farmers who have cattle. If an individual has been exposed, either through unpasteurized milk or by assisting at the delivery of calves, Q-fever can be a possibility. Recurrent episodes of fever, pulmonary symptoms, and bacterial endocarditis can all be caused by Q-fever.

Although there is no history of foreign travel in this patient, travelers' diseases must be kept in mind. Malaria has become endemic in northern San Diego County and can no longer be considered solely a disease of travelers. Additionally, malaria can strike many years after the individual has been infected. There has been one case reported of an individual, after having left the malarial endemic area 23 years ago, developing infection with Plasmodium malariae. Toxoplasmosis, particularly in immunosuppressed individuals, can produce prolonged fever. Amebiasis will present with a fever of unknown origin in the setting of an amebic hepatic abscess. Often, the patient may have right upper quadrant tenderness, and an abdominal CT scan should suggest the right diagnosis. Other diagnoses that must be considered in travelers include leishmaniasis, schistosomiasis, and trypanosomiasis.

Endemic fungal diseases should be considered: coccidioidomycosis on the West Coast, histoplasmosis on the East Coast, and blastomycosis in the Southern states. Let me remind you that it is not necessary to be living in one of the endemic areas to be affected by the endemic organism. Many people do a great deal of traveling, either as part of their occupation or for recreation, and subsequently are exposed to a wide variety of diseases. Additionally, meteorologic events can spread endemic diseases far beyond their customary areas. A good example of this was the dust storm of 1976, which carried coccidioidomycosis as far away as Sacramento.

Osteomyelitis, particularly osteomyelitis of the spine, can be difficult to diagnose. We recently had a patient with salmonella osteomyelitis whose presentation was very perplexing, and it took us 9 months to arrive, at a diagnosis. Mycobacterial osteomyelitis can also be very indolent.

Consider now the collagen vascular diseases. Systemic lupus erythematosus is generally a disease of younger people, predominantly women. Fever of unknown origin would be a somewhat unusual presentation of systemic lupus erythematosus. Rheumatoid arthritis, particularly when it is extra-articular, may present as a fever of unknown origin. Temporal arteritis is a disease being diagnosed more frequently, predominantly because it is being considered more frequently in the differential diagnoses. The presentation of temporal arteritis can be very subtle, and includes fever of unknown origin.(2) A patient need not present with visual symptoms, headaches, or the typical jaw claudication. Polymyalgia rheumatica very commonly presents with stiffness and pain in the proximal musculature, particularly about the shoulders and hips. The diagnosis of temporal arteritis requires a high index of suspicion.