Pustular allergic contact dermatitis from minoxidil

Noneczematous Contact Dermatitis

“…Nevertheless, allergic pustular reactions are known from nitrofurazone [104], black rubber [105], and minoxidil [106]. The latter has been described in a woman who developed a vesicopustular eruption on the forehead after applying 2% minoxidil solution.…”

Minimizing the Risks of Missing a Contact Allergy

“…In addition, other forms of expression are known [4, 5, 6], caused by both professional and nonprofessional allergens, such as erythema-multiforme-like lesions or urticarial papular plaques; examples of such allergens are tropical woods and many kinds of plants, local medication (fig. 2) – including steroidal [7, 8]and nonsteroidal anti-inflammatory drugs [9, 10, 11]– lichen-planus-like and lichenoid eruptions, the classic causes being color developers (photography) and metals, the last also being responsible for granulomatous and pustular reactions, although flavorings, synthetic resins [12], textile allergens [13]and topical medications [14]have occasionally been reported in this regard. Lymphomatoid contact dermatitis [15]can also occur and has recently been reported to be induced by metals [16]and textile dyes [17]; pigmentation disturbances, both hyperpigmentation and hypopigmentation (leukoderma), have been associated with several chemicals [18, 19]; even pemphigoid lesions can express a contact allergy [20].…”

Pustular allergic contact dermatitis from topical minoxidil 5%

“…Topical solution of minoxidil is usually well tolerated. However, pruritus, irritative dermatitis, scaling or dryness of the scalp and exacerbation of seborrhoeic dermatitis have been reported, overall at the onset of therapy 3–5 . In addition, occupational allergic contact dermatitis, 6 photoallergic contact dermatitis, 7 pigmented contact dermatitis, 8 and pustular allergic contact dermatitis 3 have also been described.…”

“…Pustular allergic contact dermatitis from minoxidil was first reported in 1998 3 . It has distinct histopathological features: mild spongiosis, perifollicular lymphocytes, histiocytes, eosinophils and areas of reticular degeneration 3,5 . Pustular contact hypersensitivity reactions from fluorouracil, nitrofurazona and isoconazole nitrate have also been reported 5 .…”

“…Pustular contact hypersensitivity reactions from fluorouracil, nitrofurazona and isoconazole nitrate have also been reported 5 . Pustular patch test reactions are common with metals and they may be allergic as well as irritant 3 . In contrast to allergic contact dermatitis, atopic patients tend to develop irritant contact dermatitis more often than non‐atopics 4 .…”