Occupational protein contact dermatitis with type I allergy to different kinds of meat and vegetables

Even though occupational protein contact dermatitis is not an uncommon finding in occupational dermatology, reports about multiple sensitizations are rare. High-molecular-weight substances such as proteins can pass the epidermis only if it is damaged and cause a sensitization. In a high percentage of case, atopic dermatitis might be the cause of this damage but cannot be regarded as the only cause. An interesting case is presented that was carefully worked up.

Scratch, intracutaneous, and prick or prick-to-prick tests with native occupational allergens were performed as single tests. The patient was patch-tested with the European Standard Series. The determination of allergen-specific IgE was performed by ImmunoCAP. The results were subdivided into six classes. In addition, oral provocations with relevant allergens were performed.

The skin tests showed positive type I allergies to beef, lamb, horse, and pork meat, to pork and horse blood as well as to rye and wheat flour, raw potato, and pasta. Weak positive reactions could be found for fowl, duck, goose, and turkey in intracutaneous testing. The ImmunoCAP showed elevated specific IgE values for pork meat, raw potato, and rye and wheat flour. The oral provocation did not show any systemic or skin change.

This case report demonstrates how an initial case of contact urticaria turns into protein contact dermatitis. It shows that the diagnosis can be made by means of scratch or prick tests with native occupational allergens. The determination of allergen-specific IgE by ImmunoCAP might be helpful, but a negative result does not exclude protein contact dermatitis.