Is Anisakis simplex responsible for chronic urticaria?

The association of chronic urticaria (CU) to parasitic infestations has been poorly studied. Recently, sensitization to the parasite larva Anisakis simplex has been described as the cause of acute urticaria and anaphylaxis. The aim of this work was to study the relationship between sensitization to A. simplex and CU. One hundred one patients with CU were studied. Data of possible contacts with A. simplex were collected and the usual CU study was performed. Furthermore, total and specific immunoglobulin E (IgE; Pharmacia CAP system IGE fluorescence enzyme immunoassay: CAP) to A. simplex, Ascaris lumbricoides, Echinococcus granulosus, and Toxocara canis were determined as well as skin-prick test with A. simplex and serology to E. granulosus. In accordance with the results of the CAP to A. simplex, the patients were divided into two groups, positive and negative, and, subsequently, subdivided into two other subgroups that were alternatively told to stop eating fish or seafood in their diet or to continue with their normal diet. Checkups were performed at 6, 12, and 18 months. Thirty-five percent of the patients had positive skin tests to A. simplex, and CAP to A. simplex was positive in 55%. The fish-eating habits, acute or chronic gastrointestinal disease, and the background of abdominal surgery were not related to the results of the CAP and/or skin test to A. simplex. A total of 21.8% of all the patients had detectable CAP to A. lumbricoides, 91% of whom had positive CAP to A. simplex. Three patients had specific IgE to T. canis and five patients had specific IgE to E. granulosus, in the absence of positive serology. All had specific IgE to A. simplex. Present infestation could not be proved in any of them. The clinical evolution and variations of CAP to A. simplex and of total IgE were not statistically different among the groups during the 6, 12, and 18 months of the study. The percentage of sensitization to A. simplex in patients with CU is elevated and determines the sensitization to other parasites because of cross-reactivity. We have not found any causal relationship between the presence of specific IgE to A. simplex and CU. The clinical importance of this finding in this disease is still undetermined.

Acute IgE-mediated generalized urticaria-angioedema after topical application of povidone-iodine.

Povidone is a synthetic polymer mainly used as a dispersing or suspending agent for many pharmaceutical products. It is also used as a carrier for iodine. In many countries it is not mandatory its inclusion in drug labels so many adverse effects may be under diagnosed. Povidone-iodine used as a topical antiseptic solution may produce allergic contact dermatitis and irritation. Povidone, when systemically administered may deposit in tissues causing local lesions and pain. Three cases of immediate hypersensitivity to this agent have been reported. We present a patient who developed generalized urticaria and angioedema immediately after the first topical use of Betadine (povidone-iodine) on a right arm wound. The positive skin prick test to Betadine and povidone extract and the demonstration of serum specific IgE to povidone, confirmed an IgE-mediated hypersensitivity.

Allergy to cow's milk with onset in adult life.

We report a 29-year-old patient with a history of asthma that is sometimes accompanied by urticaria, which is related to the ingestion of milk products. Once these were excluded from his diet no symptoms were observed. Skin tests, specific IgE, histamine release, and oral food challenges were positive to cow's milk and its fractions.