Allergic contact eczema from topical corticosteroids.

Area of Science:

• Dermatology
• Clinical Pharmacology

Background:

• Topical corticosteroids are mainstays in eczema and psoriasis treatment.
• Some patients exhibit unresponsiveness or paradoxical reactions to topical steroids.
• Allergic contact dermatitis to topical steroids is a recognized complication.

Purpose of the Study:

• To investigate allergic reactions to topical steroids in patients with refractory eczema or steroid-induced reactions around psoriatic lesions.
• To assess the stability of topical steroids in ethanolic solutions used for testing.

Main Methods:

• Epicutaneous testing was conducted on 105 patients using therapeutic and ten-fold diluted concentrations of topical steroids in ethanol.
• Patients were selected based on non-response to topical corticosteroids or steroid-induced reactions.
• Chromatographic purity analysis was performed on steroid solutions after one month of refrigerated storage.

Main Results:

• Five out of 105 patients (4.8%) demonstrated allergic reactions to one or more tested steroids.
• One patient sensitive to clobetasol-17-propionate reacted only to the lower concentration.
• Significant degradation of steroid purity (down to 75%) was observed in refrigerated ethanolic solutions within one month.

Conclusions:

• Allergic contact dermatitis to topical steroids is a potential issue in specific patient populations.
• The concentration of the steroid may influence the allergic reaction.
• Instability of topical steroids in ethanolic solutions poses a challenge for accurate diagnostic testing and requires careful consideration of storage and preparation.