Neoprene allergy

Synonym(s)

DBTU; Neoprene; N,N'-dibutyl-diamino-thiomethanone; N,N'-dibutylthiourea

Contact allergic eczema on wearing neoprene materials (e.g. diving suits).

A 22-year-old patient, after wearing his diving suit (wetsuit) several times on holiday, noticed flat, generalized, massively itchy skin symptoms at the contact points. After wearing the suit again, these symptoms intensified, wetted in individual areas and also manifested themselves in areas not covered by the suit.
After the suit was not worn for several days, the skin changes gradually receded, but relapsed promptly and severely after wearing another wetsuit.
Diagnosis: The epicutaneous test showed a positive reaction to the neoprene material and to dibutylthiourea (DBTU) after 72 hours. Substances of the standard series, other substances of the rubber series, leather and textile dyes and 4-phenylenediamine did not show a positive reaction.
Summary: DBTU, as well as other thioureas, are used in the production of neoprene as so-called rubber additives (see also latex allergy), as vulcanization accelerators and antioxidants.
Note: Thioureas are used in rubber and latex gloves, copying paper, cleaning agents and anti-rust agents. Cross-reactions between the different types of rubber. Thiourea DBTU, diphenyl- and diethylthiourea are not known. For patients with contact sensitisation to neoprene it is recommended to include thioureas in the tests in addition to the standard series, other vulcanisation accelerators and dyes (see also Allmiral).