THE EFFICACY OF CLOBETASOL PROPIONATE WITH VARYING DILUTIONS OF EMOLLIENT DETERMINED BY HISTAMINE WHEAL SUPPRESSION TEST

Abstract

Background:

The ability of steroids to reduce the histamine wheal was used to assess the efficacy of topical clobetasol propionate with varying dilutions of emollients.

Aim:

To determine the wheal-suppressing ability of topical clobetasol with varying dilutions of emollient.

Materials and Methods:

It was a double-blinded randomized study. Twenty-five volunteers were included in the study. Five syringes of 5 ml were taken and the syringes were loaded with either clobetasol propionate 0.05%, emollient, or clobetasol propionate with emollient in dilutions of 1:1, 1:2, and 1:3. The syringes were coded 1 to 5. Five squares of 3 × 3 cm were marked on the flexor aspect of the forearm of the volunteers. After randomization, half fingertip unit of the cream was applied within each square uniformly. Three hours later histamine prick test was performed by the standard method. The wheal was measured after 15 min and the results were recorded. After decoding, results were statistically analyzed by analysis of variance.

Result:

The decrease in wheal suppression of steroid with emollient (1:1) was same as topical steroid and the wheal suppression decreased with increasing dilutions of steroid.

Conclusion:

We conclude that steroids and emollients can be mixed in equal proportion (1:1) and the effect is same as steroid alone and increasing dilution of steroids with emollients was not effective in suppressing the wheal.

Introduction

Topical corticosteroids are widely used in various dermatological conditions. By diluting the steroids with emollients, we can decrease the amount of steroids used and thereby reduce the side effects of steroids especially when used in patients with dry scaly dermatoses.[1] The ability of the steroids to inhibit the size of histamine-induced wheal was used to assess their efficacy.[2] This study was conducted to determine the effect of steroids diluted with emollient in the concentration of 1:1, 1:2, and 1:3 by the histamine wheal suppression test.

Materials and Methods

A randomized double-blinded study was conducted on 25 volunteers who had not used systemic or tropical steroids and antihistamines for atleast 8 weeks.

Five syringes each of 5 ml were taken. The syringes were loaded with clobetasol propionate 0.05% (diplene), emollient-containing propylene glycol 15 mg, diazolidinyl urea 1.5 mg (emolene), or Diplene with Emolene in dilutions of 1:1, 1:2, and 1:3. The syringes were coded 1 to 5 [Figure 1].

Figure 1.

Syringes loaded with steroid, emollient, steroid with emollients in dilutions of 1:1, 1:2, and 1:3

A template with five apertures (3 × 3 cm) cut 2 cm apart was placed on the forearm and the squares were outlined with a marker pen [Figure 2].

Figure 2.

A template with five squares placed on the forearm

After randomization, half fingertip unit of the prepared cream which was loaded in the syringe was applied in each square. Three hours later histamine prick test was performed because clobetasol propionate has the maximum wheal suppression at the end of 3 h.[2] Prick test was performed by placing a drop of 0.1% histamine solution on the test site skin was pricked through the histamine solution with a lancet. The tip was kept parallel to the skin surface and the skin was lifted by tenting the lancet by 45 to 60 degrees. The size of the wheal was recorded in millimeters after 15 min and the mean size was calculated by measuring the maximum diameter and the orthogonal diameter of the wheal with a transparent scale. At the end of the study, the decoding was done and results were tabulated.

Results

The mean diameter of the wheal after applying steroids with various dilution of emollient is shown in Table 1. The combination of steroids with varying dilutions of emollients (P value) in comparison to steroid alone is shown in Table 2. The results were analyzed by analysis of variance.

Table 1.

The mean diameter of the wheal after application of steroids with various dilution of emollient

Table 2.

The combination of steroids with varying dilutions of emollients (P value) in comparison to steroid alone

Discussion

Topical steroids are widely used in various dermatological conditions. For extensive areas of dermatoses, the amount of steroids used is comparatively more and the side effects are also high. The extensive and prolonged use of steroids may also produce drying of the skin. This can be minimized by addition of an emollient to the steroid. The first rationale for combining clobetasol propionate with a moisturizer that includes an emollient, dimethicone, and a humectants is that treatment of a dry scaly dermatoses may contribute to overall clinical improvement.[3] This combination of steroids and emollient have been proved to be useful in various dermatological conditions such as atopic dermatitis[4] and mastocytosis.[5] In atopic dermatitis, the dry skin has diminished water-binding capacity, higher transepidermal water loss, and decreased water content compared with normal skin and it may worsen dermatitis. The degree of epidermal hydration can directly affect the penetration of steroids through the skin.[6] Therefore, a combination of steroids and emollients can benefit the patient. High potent topical steroids can cause safety concerns such as suppression of the hypothalamic pituitary axis, acne, atrophy, purpura, and these side effects can be minimized by combining steroids with emollients. Therefore, this study was conducted to determine the effect of steroids with varying dilutions of emollients on histamine wheal.

Conclusion

From this study, we conclude that the dilution of steroid and emollient (1:1) in comparison to topical steroid alone caused a decrease in wheal suppression which was not statistically significant. Dilution of steroid with emollient 1:2 and 1:3 as compared to steroid alone did not decrease wheal suppression which was statistically significant. Steroids and emollients can be mixed in equal proportion (1:1) and the effect would be the same as that of the steroid alone.