The role of 3-dimethylaminopropylamine and amidoamine in contact allergy to cocamidopropylbetaine.
Since it has been found that all subjects with contact allergy to cocamidopropylbetaine (CAPB) have positive reactions to 3-dimethylaminopropylamine (DMAPA), and reports have appeared in literature of the sensitizing action of amidoamine in products containing CAPB, we aimed to verify the possibility that pure amidoamine may have a sensitizing role in subjects with positive reactions to CAPB. To this end, in 10 patients with contact allergy to a commercial CAPB, we tested DMAPA 1% aq. and a pure amidoamine in concentrations ranging from 0.5% aq. to 0.1% aq. The study showed that all patients with positive reactions to DMAPA reacted to amidoamine at 0.5% and 0.25% aq., while 4 of the 10 also had positive reactions to amidoamine at 0.1% aq. We consider that simultaneous allergic reaction to DMAPA and amidoamine represents cross-reactivity and hypothesize that DMAPA is in fact the true sensitizing substance, while amidoamine, which may in any case release DMAPA in vivo as a result of enzymatic hydrolysis, may favour the transepidermal penetration of the sensitizing agent. In addition, we advise that testing of CAPB be suspended, because, as suggested by chemico-structural analyses and demonstrated in vivo, when thoroughly purified, it no longer has a sensitizing action.
Foti
Caterina
C
Department of Internal Medicine, Immunology and Infectious Diseases, University of Bari, Italy. c.foti@dermatologia.uniba.it
Bonamonte
Domenico
D
Mascolo
Giuseppe
G
Corcelli
Angela
A
Lobasso
Simona
S
Rigano
Luigi
L
Angelini
Gianni
G
D000485:Allergens / Q000009:adverse effects* / Q000737:chemistry; D000588:Amines / Q000009:adverse effects* / Q000737:chemistry; D001622:Betaine / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000737:chemistry; D003358:Cosmetics / Q000009:adverse effects* / Q000737:chemistry; D003429:Cross Reactions; D017449:Dermatitis, Allergic Contact / Q000209:etiology*; D003959:Diamines / Q000009:adverse effects* / Q000737:chemistry; D006801:Humans; D010328:Patch Tests; D013329:Structure-Activity Relationship
D000485:Allergens; D000588:Amines; D003358:Cosmetics; D003959:Diamines; D001622:Betaine; C077055:cocamidopropyl betaine; C012928:3-dimethylaminopropylamine