- Andrew J Blaikiea, senior house officer,
- John Ellis, specialist registrara,
- Roshini Sanders, consultantb,
- Caroline J MacEwen, consultanta
- a Department of Ophthalmology, Ninewells Hospital, Dundee DD1 9SY
- b Department of Ophthalmology, Queen Margaret Hospital, Dunfermline KY12 0SU
- Correspondence to: Dr Blaikie
- Accepted 14 May 1997
Tarantulas are becoming increasingly popular as pets. They are widely available, easily maintained, and considered harmless as many are non-venomous. Unfortunately the popular American varieties that are less venomous have evolved highly urticarious hairs to leave on their webs and flick at predators. We describe three cases of ocular injury from urticarious hairs of tarantulas.
All three patients presented with complaints of itchy, gritty, red eyes. Two patients associated the onset of symptoms with the handling of a tarantula, and the third case was recognised only by astute history taking. Initially a similar clinical picture was seen in the three patients. The main findings were of multiple fine intracorneal hairs with an associated keratoconjunctivitis. In all three patients the right eye was more affected than the left; all the patients were right handed. One case settled quickly with topical steroid treatment, and at follow up at 36 months the patient had a normal eye. The two other patients had developed a progressive pan-uveitis still clinically active at follow up at 24 months and 72 months.
In the patients with the pan-uveitis the hairs seemed to be migrating relentlessly through the media of the eye. This has led to multiple foci of inflammation at all levels within the globe, causing corneal granulomas, iritis, peripheral anterior synechiae, cataract, vitritis, and chorioretinitis. One patient developed reduced visual acuity (6/18 N10 corrected) and raised intraocular pressure (mid-20s). At 24 months since presentation this patient is currently being treated with systemic steroids and topical anti-glaucomatous drugs and is being considered for vitrectomy and extraction of a cataract.
The chronic complicated cases were associated with handling of a Chilean Rose (Grammastola cala) tarantula (fig 1 (top)), whereas the short uncomplicated case occurred after the handling of a Thailand Black (Haplopelma minax) tarantula.
Ophthalmia nodosa secondary to tarantula hairs is rare, and previous reports, where stated, have involved Mexican Red Knee (Brachypelma smithi) tarantulas with a short lasting, anterior segment dominated, inflammatory condition with no long term sequelae.1 2 3 This condition is similar to the case involving the Thailand Black spider. The clinicopathology seen in the two other cases is, however, more chronic and serious than previous reports and more consistent with cases of ophthalmia nodosa secondary to caterpillar hairs of the Lymantriidae family.4
We studied the morphology of urticarious hairs from a Chilean Rose tarantula with a scanning electron microscope (fig 1 (bottom)). The morphology of the hairs seemed almost identical to that of caterpillar hairs and noticeably different from the phylogenetically much more closely related Mexican Red Knee spider.5 This gives credence to the suggestion that hair morphology dictates the clinical outcome.
The urticarious hairs of tarantulas are poorly recognised as potential ocular irritants. Interestingly and alarmingly, Chilean Rose tarantulas are the most popular and widely available spiders on the market because of their hardiness, docility, and apparently harmless, non-venomous nature. They are often bought for children.
Our clinical experience suggests that the transfer from spider to hand to eye of urticarious hairs form the Chilean Rose tarantula may result in devastating ocular inflammation. We recommend not handling tarantulas routinely. If people must handle tarantulas then we suggest that they wear gloves, avoid rubbing the eyes during handling, and thoroughly wash their hands after handling to minimise the transfer of hairs. Raising awareness of this issue among those selling tarantulas and owners will hopefully prevent further cases.
We thank staff in the entomology department of the Natural History Museum, London (David Carter (caterpillars) and Paul Hillyard (tarantulas)); Gordon Milne, chief medical laboratory scientific officer, department of pathology, Ninewells Hospital; and Gordon Spiers, Edinburgh Butterfly and Insect World, Lassawade, Midlothian.
Conflict of interest: None.