Dimetindene

Dimetindene gel is the first thing people grab in a Spanish pharmacy after a mosquito summer: Fenistil, Dermapic, Dimestil. The AEMPS ficha técnica frames the indication broadly: relief of itch in dermatoses, urticaria, insect and marine animal bites, in adults and children from 1 month, applied 2 to 4 times a day. The evidence base for topical antihistamines is modest. The experimental work by Lever and Marks (Skin Pharmacol 2009) showed that dimetindene gel reduces itch and the weal and flare reaction in models of artificially induced pruritus – that confirms the mechanism but does not replace clinical trials on real bites. In practice the gel relieves through antihistamine action and cooling, while a strong reaction calls for an oral antihistamine. The ficha asks to avoid sun on treated areas.

ICD-10: T63.4

The AEMPS ficha técnica includes small sunburns and small superficial burns among the indications: the gel reduces itching and gives a cooling sensation. The limits, though, are firm. It may only be applied to intact skin – with blisters, weeping or an open surface the gel is not used. Extensive burns need a doctor's assessment rather than a pharmacy product. The gel contains benzalkonium chloride, which itself irritates skin, and it is not applied to mucous membranes. Treated areas must be kept out of the sun. If the burn covers a large area, has blisters, involves a child or an older person, or affects the face, hands, feet, perineum or joints, an examination is needed.

ICD-10: T20-T32 · ICD-11: ND90-ND9Z