When irritants are applied to the scalp they are expected to induce an allergic reaction. This allergic reaction draws the T lymphocytes away from the follicle in order to deal with the irritant. The hair follicle then has a chance to regrow new hair. It is theorized that this how irritants work.
Study involving irritants.
Allergic and irritant contact dermatitis compared in the treatment of alopecia totalis and universalis. A comparison of the value of topical diphencyprone and tretinoin gel.
Ashworth J; Tuyp E; Mackie RM
University Department of Dermatology, Western Infirmary, Glasgow, U.K.
Br J Dermatol 1989 Mar; 120 (3): 397-401
LANGUAGE OF PUBLICATION
Diphencyprone is a potent topical sensitizer, but is non-mutagenic in the Ames test (unlike dinitroclorobenzene) and remains relatively stable in solution (unlike squaric acid dibutyl ester). Seventeen patients with total loss of scalp hair (eight alopecia totalis, nine alopecia universalis) were treated by maintaining on one side of the scalp an allergic contact dermatitis induced by 2,3 diphenylcyclopropenone-I (‘diphencyprone’), and on the other side an irritant contact dermatitis using tretinoin gel (Retin A). After 20 weeks, treatment with tretinoin was stopped and diphencyprone was applied bilaterally for a further 10 weeks. Satisfactory regrowth of terminal hair on the scalp was achieved in only one patient. Eyebrow, eyelash and beard regrowth was achieved in one individual whilst in another, moderate, but not cosmetically satisfactory, scalp regrowth took place. In no patient did regrowth take place at tretinoin treated sites until after diphencyprone was substituted. (AUTHOR)
MJTR: Alopecia DT. Cyclopropanes TU. Dermatitis, Contact ET. Tretinoin TU.
MNTR: Administration, Topical. Adolescence. Adult. Aged. Child. Child, Preschool. Comparative Study. Female. Human. Male. Middle Age. JOURNAL ARTICLE
RNUM: 0 (Cyclopropanes); 302-79-4 (Tretinoin); 886-38-4 (diphenylcyclopropenone)
IDEN: ISSN: 0007-0963. JOURNAL-CODE: AW0. ENTRY-DATE: 890620. JOURNAL-SUBSET: M. IM-DATE: 8908.