Sir,

We present a case of papillitis caused by Lyme disease in the UK. We also highlight the increased risk of Lyme disease in cat owners.

Case report

A 50-year-old man presented with a 10-day history of central blurring of vision in his left eye. He had noted a rash on his right forearm 6 months previously. There was no definite history of a tick bite or of visiting high-risk areas, but his cat had ticks. Unaided vision was 6/6-3 right and 6/24 left improving to 6/12 with pinhole. There was a mild left relative afferent pupillary defect, a paracentral scotoma inferior to fixation, mild impairment of colour vision, and a pink swollen optic disc on this side.

Lyme disease antibody titres were positive by ELISA and Western blot methods, confirmed by a reference laboratory. The following investigations were normal or negative: full blood count, ESR, auto-antibody screen, coagulation screen, angiotensin converting enzyme, anti-neutrophil cytoplasmic antibody, syphilis serology, and lupus anticoagulant. The patient was treated with a 2-week course of intravenous ceftriaxone. The visual acuity however did not change with treatment.

Comment

Lyme disease can mimic many ophthalmic conditions. It has been reported to cause eyelid oedema, conjunctivitis, keratitis, episcleritis, anterior uveitis, vitritis, choroiditis, endophthalmitis, neuroretinitis, exudative retinal detachment, retinal vasculitis, optic neuritis, optic atrophy, pseudotumour cerebri, paresis of cranial nerves, and orbital myositis.1, 2 Optic neuritis in Lyme disease may or may not respond to treatment with antibiotics.2

In the mid-1970s, Dr Allen Steere and colleagues noted that a significant number of patients with Lyme disease had cats and had noted ticks on their pets, compared with their unaffected neighbours.3 Lyme disease is now known to occur in cats, and Borrelia burgdorferi has been isolated from the tissue of adult and nymphal ticks removed from domestic cats.4, 5 The increased risk of Lyme disease in cat owners is not widely known. This case report may represent Lyme disease causing papillitis transmitted from the patient's cat.