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150 Scrub Typhus Associated with Systemic Lupus Erythematosus: A Case Reportsounds were normal and there were no murmurs.The chest examination was normal. There was nohepatosplenomegaly and neurological examinationwas normal.Hematological tests showed hemoglobin of 8.4gm/dl, white blood cell count of 2.2 x 10 9 /ml anda platelet count of 230 x 10 9 /ml. ESR was 118 mm/hr, CRP negative, coagulation profile normal andCoomb’s test negative. Serum iron was 5 µmol/l,bilirubin was normal with an AST of 151 iu/l, ALT of87 iu/l and ALP of 423 iu/l. Urine microscopy wasnormal, the pH 5 and the 24-hour urine protein was0.19 g/day. Complement tests showed a C3 of 78(normal range 75-135) mg/dl and C4 of 16 (normalrange 12-72) mg/dl. Hepatitis profile, monospottest, brucella antigen test and Widal test werenegative. Chest radiograph, the abdomen and pelvicultrasound were normal. The rheumatoid factor(RF) IgM titer was 26 µmol/ml (n < 20), RF IgG 14µmol/ml (n < 20), RF IgA 10 µmol/ml (n < 15), ANA1/320 (speckled pattern), and anti-dsDNA antibody76 IU/L. A clinical diagnosis of SLE was made andprednisolone was started at a dose of 40 mg per day.The patient felt well, the pain in the joints improvedbut the fever persisted. White blood cell count roseto 14.4 x 10 9 /ml, liver enzymes remained high andthe CRP became positive on repeated examination.An associated infective process was then consideredand a diagnosis of pyrexia of unknown origin wasentertained.Repeated chest radiographs and blood cultureswere normal. Further blood investigations werenegative for HIV, toxoplasma, parvovirus andfungus. Gallium scan was negative. However,Weil-Felix reaction was positive for OX-K proteusantigen with a titer of 1/320, rising to 1/640 afterthree days.A definitive diagnosis of scrub typhuscomplicating SLE was made. The patient wasprescribed 500 mg of oral tetracycline every sixhours by the medical on-call team. The fever abatedwithin two days and the patient felt much better.On clinical grounds the treating team preferred notto change tetracycline to doxycycline. The generalcondition of the patient continued to improve andthe white blood cell and liver function tests becamenormal. She was discharged on oral prednisolone40 mg daily and tetracycline 500 mg qds for atotal of two weeks. On review the patient wasasymptomatic and well.DISCUSSIONSLE presenting as prolonged fever is a wellknownclinical entity. When classical clinicalsymptoms and signs are present and the appropriatelaboratory investigations are positive the diagnosisis usually straightforward. However borderlineJune 2009cases may take some time as the laboratoryinvestigations, ANA and anti-dsDNA antibody maynot be positive at the beginning of the disease [3,4] .When the diagnosis of SLE is definitive and thedisease is treated with adequate dose of steroidsand other immunosuppressant the fever settlesquickly and skin rashes gradually fade or disappearaltogether.If fever does not settle quickly or if prolongedfever occurs, the diagnosis of an associated infectionshould be entertained. In our patient, when thediagnosis of SLE was made and oral steroidsprescribed, joint pains were relieved but feverpersisted. As the ESR remained elevated, the CRPbecame positive and the liver enzymes remainedhigh, we investigated for a possible infectivecause. Serological tests revealed an associatedinfection with scrub typhus. Isolation of Orientiatsutsugamushi (O. tsutsugamushi) was not attempted.With the appropriate dose of tetracycline the patientpromptly responded and the fever abated.Many major infections complicate the course ofSLE, and scrub typhus is rarely incriminated. Scrubtyphus is a mite-borne infectious disease caused byO. tsutsugamushi. The organism is a gram-negativecoccobacillus that is antigenically distinct fromthe typhus group rickettsiae, which is distributedthroughout the Asia Pacific rim. Scrub typhus isendemic in South East Asia, Australia but found onrare occasions in the Arabian Peninsula.Patients with scrub typhus develop high fever,generalized headache, diffuse myalgia with thepresence of a skin rash or a typical necrotic lesioncalled an eschar. Sometimes there is also generalizedlymphadenopathy and splenomegaly [5] . Laboratoryfindings include leucopenia or leucocytosis,elevation of hepatic enzymes and bilirubin [5] .The pathological hallmark of scrub typhus is alymphohistiocytic vasculitis seen on biopsy of theeschar or skin rashes [6] . It is difficult to culture O.tsutsugamushi and this is done only in specializedlaboratories. Scrub typhus lasts for 14 to 21 dayswithout treatment. Severe infections may becomplicated by interstitial pneumonia, pulmonaryedema, congestive heart failure, circulatory collapse,and a wide array of signs and symptoms of centralnervous system dysfunction, including delirium,confusion, and seizures. These complications maylead to death, usually late in the second week ofthe illness. Fortunately none of these complicationswere noted in our patient who responded quicklyto tetracycline.As scrub typhus is not endemic in the ArabianPeninsula and the patient did not travel abroad,the diagnosis of scrub typhus was not consideredinitially. Furthermore, she did not rememberbeing bitten by a mite and there were no skin