A case of type IV hypersensitivity to topiramate and carbamazepine

Topiramate-induced acute bilateral angle closure and myopia: pathophysiology and treatment controversies

PURPOSE

To discuss the unusual features of topiramate-induced acute angle closure glaucoma, its pathophysiologic mechanisms, and treatment controversies, and to report the first anterior segment optical coherence tomography (OCT) of this condition.

METHODS

Literature review and case report with OCT findings.

RESULTS

Topiramate-induced angle closure is usually bilateral and associated with acute myopia; the ocular pressure is often not very highly elevated. Ciliochoroidal detachment with ciliary body anterior rotation is typically present and was demonstrated easily in our case with anterior segment OCT. Pilocarpine exacerbates this condition and peripheral iridotomy is not indicated, nor is iridoplasty. Treatment consists of replacing topiramate with appropriate medication, strong cycloplegia, and topical steroids.

CONCLUSIONS

It is important to recognize this form of acute secondary angle closure in order to treat it properly, avoiding harmful medication and unnecessary surgery.

Epicutaneous patch testing in drug hypersensitivity syndrome (DRESS)

BACKGROUND

In some patterns of cutaneous adverse drug reactions, and depending on the culprit drug, patch testing has been helpful in confirming its cause. Its value in Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) has not been established in a large cohort of patients.

OBJECTIVE

The aim of the present study is to evaluate the safety and usefulness of patch testing in DRESS.

PATIENTS/METHODS

Between January 1998 and December 2008, we studied 56 patients with DRESS induced by antiepileptic agents in 33 patients (59%), allopurinol in 19 (34%) and sulfasalazine, cotrimoxazole, tenoxicam, and amoxicillin in 1 patient each (7%).

RESULTS

A positive patch test reaction was observed in 18 patients (32.1%), of which 17 were with antiepileptics and 1 with tenoxicam. In the antiepileptic group, carbamazepine alone was responsible for 13 of 17 positive reactions (76.5%). Patch tests with allopurinol and its metabolite were negative in all cases attributed to this drug.

CONCLUSIONS

In this study, patch testing was a safe and useful method in confirming the culprit drug in DRESS induced by antiepileptic drugs, whereas it had no value in DRESS induced by allopurinol. The pathogenesis of DRESS is not yet entirely clarified, but positive patch tests suggest a drug-dependent delayed hypersensitivity mechanism.

Clinical update on contact allergy

PURPOSE OF REVIEW

The aim of this article is to review recent findings in contact allergy, regarding clinical research.

RECENT FINDINGS

The biocide methyldibromo glutaronitrile was identified to be an important sensitizer. Subsequently, it was banned from leave-on cosmetics in the European Union. Another group of important allergens that have been studied extensively included the fragrances oak moss absolute, isoeugenol, hydroxyisohexyl 3-cyclohexene carboxaldehyde and farnesol. A new fragrance mix II has been developed for standard testing, which includes the two latter compounds. Dose response studies have demonstrated broad individual variation of elicitation thresholds, dependent on the allergen concentration during induction, and other factors. Some unsuspected routes of exposure to allergens include oral, inhalational, connubial or airborne contact. Experimental studies provide a classification of newly introduced chemicals; increasingly, the local lymph node assay is supplementing and potentially replacing the guinea pig maximization test. Recent advances in occupational contact allergy include, for example, some attempts to improve diagnostics for epoxy resin and other plastic, glue, and cutting fluid components.

SUMMARY

Constant awareness for new allergens, confirmed by critical evaluation, standardization of patch test materials, and the identification of temporal patterns and subgroups at risk will improve both the diagnosis and prevention of allergic contact dermatitis.