Background-Recent years have seen increased levels of production and consum
ption of seafood, leading to more frequent reporting of allergic reactions
in occupational and domestic settings. This review focuses on occupational
allergy in the fishing and seafood processing industry.
Review-Workers involved in either manual or automated processing of crabs'
prawns, mussels, fish, and fishmeal production are commonly exposed to vari
ous constituents of seafood. Aerosolisation of seafood and cooking fluid du
ring processing are potential occupational situations that could result in
sensitisation through inhalation. There is great variability of aerosol exp
osure within and among various jobs with reported allergen concentrations r
anging from 0.001 to 5.061(mug/m(3)). Occupational dermal exposure occurs a
s a result of unprotected handling of seafood and its byproducts. Occupatio
nal allergies have been reported in workers exposed to arthropods (crustace
ans), molluscs, pisces (bony fish) and other agents derived from seafood. T
he prevalence of occupational asthma ranges from 7% to 36%, and for occupat
ional protein contact dermatitis, from 3% to 11%. These health outcomes are
mainly due to high molecular weight proteins in seafood causing an IgE med
iated response. Cross reactivity between various species within a major sea
food grouping also occurs. Limited evidence from dose-response relations in
dicate that development of symptoms is related to duration or intensity of
exposure. The evidence for atopy as a risk factor for occupational sensitis
ation and asthma is supportive, whereas evidence for cigarette smoking is l
imited. Disruption of the intact skin barrier seems to be an important adde
d risk factor for occupational protein contact dermatitis.
Conclusion-The range of allergic disease associated with occupational expos
ure to crab is well characterised, whereas for other seafood agents the evi
dence is somewhat limited. There is a need for further epidemiological stud
ies to better characterise this risk. More detailed characterisation of spe
cific protein antigens in aerosols and associated establishment of dose-res
ponse relations for acute and chronic exposure to seafood; the respective r
oles of skin contact and inhalational exposure in allergic sensitisation an
d cross reactivity; and the contribution of host associated factors in the
development of occupational seafood allergies are important areas for futur
e research.