Relapsing Fever Associated Arthritis

Relapsing fever is a spirochaetal infection (Borrelia recurrentis, louse-borne; B. hermsii, B. duttonii, B. persica, tick-borne) causing recurrent febrile episodes, with arthralgia or arthritis in a minority.

• Louse-borne disease occurs in epidemics among refugees and homeless populations (Horn of Africa); tick-borne in endemic foci (East Africa, Americas, Middle East).

• Antigenic variation of variable surface proteins causes relapses every 5 to 7 days.

• Joint involvement is usually migratory arthralgia, with true arthritis uncommon, possibly through immune mechanisms or direct infection.

• Complications: Jarisch-Herxheimer reaction, hepatic and splenic involvement, myocarditis, neurological disease, pregnancy loss.

• Abrupt high fever, rigors, headache, myalgia, arthralgia, nausea, jaundice, epistaxis and petechiae, hepatosplenomegaly.

• Fever lasting 3 to 6 days, afebrile gap of about a week, then relapses (louse-borne usually one relapse, tick-borne several).

• Large joint arthralgia, occasionally monoarthritis (knee).

• Neurological: meningitis, facial palsy, iritis.

• Thick and thin blood film (Giemsa) during fever: large spirochaetes (sensitivity 70% in febrile phase); dark-field microscopy.

• PCR for Borrelia species; serology cross reacts with Lyme and Treponema.

• Count: thrombocytopenia, anaemia; raised bilirubin, transaminases, INR; CSF if neurological signs.

• Joint aspiration if effusion to exclude septic arthritis (culture negative, spirochaetes rarely seen).

• Exclude malaria, Lyme disease, leptospirosis, typhus, brucellosis.

• Louse-borne: single dose doxycycline 100 mg (or 200 mg), tetracycline 500 mg, erythromycin 500 mg, or penicillin G procaine 600,000 units IM.

• Tick-borne: doxycycline 100 mg twice daily for 7 to 10 days, or erythromycin 500 mg four times daily; ceftriaxone 2 g daily for 10 to 14 days for neuroborreliosis.

• Pregnant women and young children: erythromycin 500 mg four times daily or penicillin.

• Prevent and treat Jarisch-Herxheimer reaction (within 1 to 4 hours: rigors, hypotension, hyperpyrexia): monitor, IV fluids, paracetamol, intensive observation; steroids and TNF antibody are not proven.

• Arthritis: NSAIDs for symptoms, which resolve with antibiotic treatment.

• Vector control (delousing, tick avoidance, repellents) and public health notification.