AbstractBackgroundThe high‐density microarray patch (HD‐MAP) promises to be a robust vaccination platform with clear advantages for future global societal demands for health care management. The method of action has its base not only in efficient delivery of vaccine but also in the reliable induction of a local innate physical inflammatory response to adjuvant the vaccination process. The application process needs to induce levels of reactivity, which are acceptable to the vaccine, and from which the skin promptly recovers.Materials and methods1 × 1 cm HD‐MAP patches containing 5000, 250‐μm long microprojections were applied to the skin in 12 healthy volunteers. The return of skin barrier function was assessed by transepidermal water loss (TEWL) and reaction to topical histamine challenge.ResultsSkin barrier recovery by 48 h was confirmed for all HD‐MAP sites by recovered resistance to the effects of topical histamine application.ConclusionsOur previous observation, that the barrier disruption indicator TEWL returns to normal by 48 h, is supported by this paper's demonstration of return of skin resistance to topical histamine challenge in twelve healthy subjects.