Allergic contact dermatitis from topical steroids

Recommendation to update the British Society for Cutaneous Allergy corticosteroid series

BACKGROUND

Patch testing is an important investigation when dermatitis is unresponsive to, or worsened by, topical corticosteroid treatment. There is a balance to be struck between testing too many allergens, which is expensive, time consuming and risks causing sensitization, and testing too few, which risks missing the diagnosis. The current British Society for Cutaneous Allergy (BSCA) corticosteroid series comprises eight allergens and was last updated in February 2007.

AIM

To review and update the BSCA corticosteroid series.

METHODS

We retrospectively analysed data from 16 patch test centres in the UK and Ireland for all patients who were patch tested to a corticosteroid series between August 2017 and July 2019. We recorded the allergens tested, the number and percentage tested to a corticosteroid series and the number of positive results for each allergen. We identified the allergens that test positive in ≥ 0.1% of selectively tested patients.

RESULTS

Overall, 3531 patients were tested to a corticosteroid series in the 16 centres. The number of allergens tested ranged from 7 to 18 (mean 10). The proportion of patch test patients who were tested to a corticosteroid series ranged from 1% to 99%. Six allergens in the 2017 BSCA series tested positive in ≥ 0.1% of patients. Nine allergens not in the BSCA corticosteroid series tested positive in ≥ 0.1% of patients.

CONCLUSION

This audit demonstrates the importance of regular review of recommended series and the significant variations in practice. The new BSCA corticosteroid series that we recommend contains 13 haptens, with the addition of the patient's own steroid creams as appropriate.

Detection of contact hypersensitivity to corticosteroids in allergic contact dermatitis patients who do not respond to topical corticosteroids

The delayed hypersensitivity development against topical corticosteroids which are used in allergic contact dermatitis (ACD) treatment is an important clinical problem. In our study, 41 ACD patients who did not show any response to topical corticosteroid treatment were patch tested with corticosteroid series and the commercial preparations of corticosteroids and their vehicles. In corticosteroid series, there were budesonide, bethametasone-17-valerate, triamcinolone acetonide, tixocortol pivalate, alclomethasone-17-21-dipropionate, clobetasole-17-propionate, dexamethasone-21-phosphate disodium and hydrocortisone-17-butyrate. We detected positive reaction to corticosteroids in 9 of our cases (22%) (5 single and 4 multiple). The sensitivity was mostly produced by tixocortol pivalate (6 patients). This was followed by triamcinolone acetonide (2 patients) budesonide (2 patients), alclomethasone dipropionate (2 patients), dexamethasone 21 phosphate disodium (2 patients) and betamethasone-17-valerate (1 patient). As a result, it should not be forgotten that the corticosteroids used to treat ACD patients may cause ACD themselves. In ACD patients who did not respond to corticosteroid treatment, routinely applying patch test with corticosteroids should be helpful in directing the treatment.

Corticosteroid contact hypersensitivity: what vehicle and concentration?

The correct concentration and vehicle for patch testing with corticosteroids is in many instances not known. The results of this study suggest that 1% in ethanol should be the initial choice, unless it can be shown that petrolatum as a vehicle is as sensitive (tixocortol pivalate and budesonide). We could find no evidence for the anti-inflammatory effects of corticosteroids inhibiting the patch test at higher concentrations. Using ethanol as the vehicle resulted in reactions developing at earlier time points than with petrolatum.

Screening for corticosteroid contact hypersensitivity

To evaluate which corticosteroids are most useful for the detection of corticosteroid contact allergy in our population, 2123 patients were patch tested with a series of 6 corticosteroids, in parallel with a standard series, and other relevant investigations. 127 patients (5.98%) were allergic to one or more corticosteroids; 96 to tixocortol pivalate, 51 to hydrocortisone butyrate, 47 to budesonide, 11 to betamethasone valerate, 11 to clobetasone butyrate and 8 to clobetasol propionate. 511 patients with negative patch tests to the limited corticosteroid series were in addition tested to a further 12 corticosteroids; only 1 of these patients reacted to a corticosteroid. A combination of tixocortol pivalate and budesonide thus detected 91.3% of corticosteroid-allergic subjects. We believe that both these allergens should be included in the standard series and that there may be a case for extending this further.

Hypersensitivity to topical corticosteroids

Contact hypersensitivity from topical corticosteroids is becoming increasingly recognized; it is present in 2-5% of the patients attending contact dermatitis clinics. The use of a corticosteroid series containing tixocortal pivalate 1% (petrolatum), to detect hypersensitivity to hydrocortisone, and other steroids 1% (ethanol), depending on local corticosteroid usage, detects the majority of cases of corticosteroid hypersensitivity. In selected cases, the use of intradermal tests further improves the diagnosis of corticosteroid hypersensitivity. Corticosteroid hypersensitivity occurs most frequently among patients with stasis dermatitis. However, corticosteroid hypersensitivity is also common in other types of dermatitis, occurring as frequently as hypersensitivity to several allergens (e.g. wool alcohols and colophony) in the European standard battery. Although hypersensitivity has mainly been reported with corticosteroids applied to the skin, reactions may also occur on mucosal surfaces, following systemic administration and with sex steroids.

Contact allergies to topical corticosteroids: 10 cases of contact dermatitis

Patients who noticed worsening of their skin disease after using topical corticosteroid preparations were patch tested both with the commercial preparation and the corticosteroid itself. Between 1987 and 1989, 10 cases of contact dermatitis due to topical corticosteroids were detected in this way. The corticosteroids wee amcinonide (2 patients), hydrocortisone butyrate, clobetasol propionate (2), betamethasone valerate (2), prednicarbate and fluocortolone (2). Patch tests with the commercial preparations and the corticosteroids themselves elicited reactions almost identical in time course and severity. Individual sensitivity seems to be more important for test results than test conditions. 9 of the 10 patients underwent further patch testing with a corticosteroid series. In 2 patients, a true cross-reaction between budesonide and hydrocortisone butyrate was found. All 9 patients showed further sensitivities to other corticosteroids. Most of the cross or concomitant reactions could be categorized into recently defined corticosteroid classes. To improve our understanding of corticosteroid sensitization, and to help the patient avoid reactions to other topical corticosteroids, a corticosteroid series should be patch tested in every case of corticosteroid sensitivity.

Allergic contact dermatitis from topical corticosteroids

22 cases of allergic contact dermatitis from topical corticosteroids were observed in Strasbourg and previously published. 7 further cases are reported here and the vehicle and concentration of corticosteroids for patch tests are discussed. A 0.1% concentration in petrolatum seemed adequate for testing the 4 molecules (triamcinolone acetonide, dexamethasone, desonide and amcinonide) responsible for the 7 new cases. In 1 case, several cross-reactions were seen. A corticosteroid screening series permits patch testing of the suspected molecule(s) in a selective way. Without this series, long delays are required to make the correct diagnosis by patch testing. We have reviewed more than 60 papers on corticosteroid allergy published up to now.