Food allergy to cocoa appears to be rare although occupational allergy in workers exposed to cocoa dust has been reported (Zuskin et al. 1998 [806]; Perfetti et al. 1997 [808]). However, self-reported allergy to cocoa appears to be common (Brugman et al. 1998 [809]). Because of this cocoa has been included in studies of the prevalence of food allergy (Young et al. 1994 [810]) and DBPCFC has been used.

It has been suggested that intolerance to cocao involves biogenic amines. However, Jansen et al. (2003) [805] found no evidence for this. Moller et al. (1984) [575] in a study of of penicillin allergy in occupationally exposed individuals showed cocoa to produce non-allergic histamine release in basophil mediator release test. Becker et al. (1981) [21] extracted a species of 20 -40 kDa (centred on 26 kDa) which activates the factor XII-dependent pathways. However, the inflamatory activity may involve polyphenols binding to complement and does not necessarily involve IgE.