Importance of Delivery Systems in Causing Cutaneous Reactions
The likelihood of reactions to a TTS may depend on the type of delivery system. Jordan performed an open-label crossover study that compared skin reactions to a scrotal testosterone TTS (which clings to the skin when warmed by body heat and does not contain adhesives or permeation enhancers) and a nonscrotal testosterone TTS (which uses adhesives and permeation enhancers). Sixty subjects reported no contact allergy during use of the scrotal TTS whereas seven (12%) of the patients experienced allergic skin reactions when using the nonscrotal system, which was applied on rotating sites on the back or upper arm. Allergy was diagnosed clinically by the presence of pruritus, induration, and erythema with infiltration, along with skin "recall" reactions at previous application sites. Four of these seven patients were changed to the scrotal system. None of these four patients experienced a reaction; thus, it was hypothesized that testosterone was not the sensitizer. However, formal patch testing was not performed. Compounds in the regular TTS, but not the scrotal TTS, included permeation enhancers (alcohol, glycerin, glycerol monooleate, and methyl laurate gelled with acrylic acid copolymer) and acrylic adhesives.
In a randomized placebo-controlled crossover study of 82 women, Ross and colleagues found that reservoir estradiol TTSs caused more irritation than matrix estradiol TTSs. Seventy-two women completed the study. Nine (13%) discontinued using both reservoir and matrix TTSs because of skin reactions. Twenty-six patients (36%) discontinued the reservoir TTS whereas only 4 patients (6%) discontinued the matrix TTS. Patch testing was not performed. Batta and Foulds speculated that this study's patients, all of whom had previously discontinued the use of the reservoir TTS, had already been sensitized to one or more of the components of the TTS. The matrix TTS contained different ingredients to which the patients had not previously been exposed, except for estradiol, which is not a common sensitizer. Thus, the results of this study may not be applicable to patients who have never used an estradiol TTS.
Dermatitis. 2006;17(3):109-122. © 2006 American Contact Dermatitis Society
Cite this: Cutaneous Reactions to Transdermal Therapeutic Systems - Medscape - Sep 01, 2006.