Is tioconazole contact dermatitis still a concern? Bringing allergic contact dermatitis caused by topical tioconazole back into the spotlight

Delayed access and provision of dermatological care as a collateral damage of COVID‐19‐related fear: Allergic contact dermatitis to fluconazole

“…Azole antifungals are classified into two groups: imidazoles (including tioconazole, clotrimazole, econazole, ketoconazole, and miconazole) and triazoles (including fluconazole, the most representative drug). Although many cases of allergic contact dermatitis to topical tioconazole were reported between 1989 and 1996, cases have gradually decreased over time, probably due to reduced sales 3 . However, recent reports show a fresh increase in cases of periungual contact dermatitis, some of which are associated with nail onychomadesis 3,4 …”

Onychomadesis secondary to allergic contact dermatitis to tioconazole contained in a nail lacquer: Description of three cases

“…Allergy to tioconazole was repeatedly reported in the literature in the years between 1989 and 1996, but showed a decreasing trend thereafter. The most recent paper in this field describes a series of 8 cases of ACD to tioconazole nail solutions . Generally, most published cases of allergy to topical tioconazole were related to the use of medicated nail solutions, but onychomadesis was never described in these patients.…”

“…A recent paper by Stingeni et al showed, based on computerized conformational analysis, that the numbers and locations of positive and/or negative polarized areas of methylisothiazolinone and tioconazole are similar, suggesting a possible cross‐reactivity between these molecules. As recently stated by Pérez‐Mesonero et al, contact dermatitis caused by tioconazole is still a concern and the lack of publications on the topic does not necessarily mean that it no longer exists. Indeed, tioconazole is frequently used as a self‐medication for the treatment of suspected onychomycosis, sometimes without medical advice.…”

“…The most recent paper in this field describes a series of 8 cases of ACD to tioconazole nail solutions. 5 Generally, most published cases of allergy to topical tioconazole were related to the use of medicated nail solutions, but onychomadesis was never described in these patients. One of our patients also showed a positive reaction to methylisothiazolinone, of no apparent clinical relevance.…”

Contact Allergy—Emerging Allergens and Public Health Impact

“…Some decades ago, tioconazole was found to be a significant contact allergen; in 2019, a new series of 8 patients with onychomycosis treated with 28% tioconazole solutions was reported from Spain, with patch tests using tioconazole 1% pet. being positive [196]. Additionally, undecylenic acid, which is also contained in the above nail solutions (but tested negative in the 2 patients tested with it) may be a cause of ACD from nail solutions [197].…”