A man in his sixties was hospitalised with vision loss due to second-stage syphilis. Ocular syphilis is a rare and serious condition. The incidence of syphilis is increasing, and since delayed diagnosis can result in permanent visual impairment, syphilis should be considered as a possible cause in patients with vision loss.
The patient contacted A&E because he had experienced relatively acute, painless loss of vision in his right eye four days previously. He described it as pronounced, darkened and blurry vision. An examination by an ophthalmologist revealed substantially reduced visual acuity in the right eye. The patient managed to count fingers at 2 metres. Visual acuity in the left eye was 1.2, so completely normal. Swinging flashlight test revealed a relative afferent pupillary defect in the right eye, i.e. that the pupils constricted less when the right eye was directly illuminated than when the left eye was directly illuminated. This suggested optic nerve damage or a large retinal injury of the right eye.
Field of vision testing revealed central scotoma of the right eye. The ophthalmologic exam was otherwise normal. No signs were found of uveitis or vasculitis. The retina and macula were normal in appearance. The optic nerve head was well defined with a physiological excavation (cup/disc ratio of 0.5). The ophthalmologist concluded that the vision loss was due to optic nerve involvement. As there was no pain, and the loss of vision was sudden, an ischaemic cause was suspected.
Temporal arteritis is an important differential diagnosis in cases of ischaemic involvement of the eye and acute vision loss in patients over the age of 50. Untreated temporal arteritis can cause irreversible blindness, and in rare cases stroke (1). The patient's history was scrutinised with the possibility of temporal arteritis in mind.
The patient related that he had an 'infection in his body' that the doctors could not identify. He had felt seriously ill for about four and a half months. He had no energy, experienced hot flashes, diarrhoea, headache, pain in the abdomen and large muscle groups, and in the gums and throat. He himself was sure it was caused by vitamin deficiency following gastric bypass surgery he had had earlier. His family doctor had therefore referred him to the Centre for Obesity. A rheumatologist and an endocrinologist had previously examined him without arriving at a diagnosis. However, enlarged lymph nodes were found in his neck and a rash had been present on his back. Blood tests showed an elevated sedimentation rate (SR) and C-reactive protein (CRP), but no definite cause was found.
When examined by the ophthalmologist he had a pink, scaly maculopapular rash over his entire back (Figure 1). A weaker pulse was palpated in the right temporal artery, and the right temple was tender to palpation. Blood tests showed anaemia with Hb 10.4 g/dL (reference range 11.1–14.9 g/dL) and elevated inflammatory parameters with CRP 23 mg/L (0–5 mg/L) and SR 50 (2–20 mm).
Elevated SR and CRP, malaise, age, optic nerve involvement coupled with tenderness to palpation and weakened temporal artery pulse aroused suspicion of temporal arteritis. The patient was admitted to the Department of Ophthalmology, and started treatment with prednisolone 80 mg once a day and acetylsalicylic acid 75 mg once a day as prophylaxis against further ischaemic events. Temporal artery and dermal biopsies were performed. The following day the patient was transferred to the Department of Rheumatology, where steroid therapy was continued with intravenous methylprednisolone 1 g per day.
An expanded patient history revealed that he had been in Thailand five months previously and had had unprotected intercourse with multiple women. Two months later a non-tender, hard lesion had developed on his penis, and several weeks after that he developed a rash on chest and back. The penile lesion resolved after two weeks, but his general malaise and rash persisted.
Tests were conducted for chlamydia, gonorrhoea, HIV, hepatitis B and C, tuberculosis and syphilis, as well as for antinuclear antibodies (ANA) and antineutrophil cytoplasmic autoantibodies (ANCA). A CT angiogram was performed to evaluate for large-vessel vasculitis. The scan revealed a 55 mm dilated thoracic aortic aneurism, but there were no inflammatory changes in the large blood vessels suggestive of vasculitis.
Syphilis antibody tests, Treponema pallidum particle agglutination assay (TPPA) and rapid plasma reagin (RPR) tests were positive in very high titres. Temporal arteritis was deemed unlikely, and methylprednisolone was discontinued.
The patient was transferred to the Department of Infectious Diseases, where a lumbar puncture was performed. The cerebrospinal fluid showed an increased leukocyte count, 32 · 106/L (0–5 · 106/L), increased protein, 0.65 g/L (0.15–0.50 g/L), and positive TPPA antibodies. This was consistent with neurosyphilis, and the patient was diagnosed with secondary stage syphilis with optic neuritis. The patient received intravenous treatment with penicillin 3 g x 4 for 12 days.
The temporal artery biopsy showed no signs of temporal arteritis, and the skin biopsy showed non-specific inflammation. The rash disappeared over the course of two months. Follow-up by the ophthalmologist four months after treatment showed almost total resolution of the central field of vision deficit, and visual acuity had improved from finger counting at 2 m to visual acuity 0.8. Follow-up blood tests by an infectious disease specialist one year later revealed a complete absence of RPR antibodies, indicating successful treatment for neurosyphilis.
The patient has consented to the publication of the article.
The article has been peer-reviewed.