Abstract
Purpose :
To evaluate cases suggestive for bilateral allergic conjunctivitis with standard culture-negative tests non-responders to usual antiallergic therapies.
Methods :
The clinical cases of 3 patients with bilateral signs and symptoms of allergic conjunctivitis unresponsive to antihistamines, membrane stabilizers and steroids instilled for at least 2 weeks and with a previous negative microbiological swab for bacteria and fungi are presented. After a 48-hour washout, tarsal conjunctival scraping is carried out for the evaluation of the inflammatory infiltrate in OM and for the identification of any microbial form in SEM, based on the morphology and size of the microorganisms.
Results :
OM examination showed signs of persistent non-allergic inflammation with lymphocytic and neutrophilic infiltrates, while SEM allowed the identification of Mycoplasma in two cases and Chlamydia in the other one. Mycoplasma conjunctivitis were treated with topical tetracyclines every 4 hours and hydrocortisone BID for 3 weeks, while Chlamydial infection with oral tetracyclines associated with local tetracyclines/sulfamethylthiazole every 4 hours for 4 weeks. In all cases there was clinical and microbiological resolution upon SEM evaluation at the end of the treatment.
Conclusions :
The clinical picture and culture examination do not always allow for a correct diagnostic-therapeutic evaluation. In the cases described, the microbial origin seemed to be excluded by the clinical characteristics and routine microbiological investigations, but the insufficient therapeutic response toantiallergic drugs left the etiopathogenetic question unresolved. Mycoplasmas are small aerobic bacteria, which are not isolated in common culture media, whose antigens can cause hypersensitivity reactions,.generating allergic-type clinical pictures. Similar reactions can occur in cases of Chlamydial infection, the diagnosis of which is generally made by specific methods (direct IF, PCR or SEM). The examination of the conjunctival scraping in OM and SEM allowed the correct etiological identification and the setting of a targeted and effective therapeutic strategy.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.