Occupational asthma due to piperazine citrate.

BACKGROUND: Piperazine is a secondary heterocyclic amine that may give rise to occupational asthma of uncertain mechanism. METHODS: We report on a 42-year-old woman, a process operator in a chemical factory, who developed work-related symptoms of rhinitis and asthma upon exposure to piperazine citrate. She remained symptom free during holidays and days off work. RESULTS: Skin prick test with piperazine citrate was positive. Specific inhalation challenge with piperazine citrate at a concentration of 5 mg/m3 for 30 minutes elicited an isolated late asthmatic response. Airway hyperresponsiveness to methacholine significantly increased 3 hours after the piperazine challenge, preceding the late asthmatic response. CONCLUSION: This patient had developed occupational asthma caused by piperazine, as confirmed by the specific inhalation challenge test, possibly due to an immunological mechanism.

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.

Piroxicam-induced photodermatitis. Cross-reactivity among oxicams. A case report.

BACKGROUND: there is a group of patients with contact allergy to thimerosal (thiosalicylic acid and ethylmercuric chloride), thiosalicylic acid sensitized, who develop photodermatitis to piroxicam. We present a case which we have investigated cross-reactivity among different oxicams. METHODS AND RESULTS: a 44-year-old man with contact allergy to thimerosal. A few hours after the intake of Feldene (piroxicam) while running outside, developed a papuloerithematosus exanthema in the neck, knees and forearms, and microvesicles on the finger webs, that became descamative a few days later. Oclusive patch tests with thiosalicylic acid, mercury, piroxicam, tenoxicam, droxicam and meloxicam and photopatch test with the oxicams were performed. Patch tests with thiosalicylic acid and piroxicam were positive and negative with the others. All the oxicams photopatch tests were positive. CONCLUSIONS: we present a case of photodermatitis and dermatitis to piroxicam, in a patient with contact allergy to the thiosalicylic moiety of thimerosal, in which cross-reactivity with the other oxicams have been demonstrated. In cases of oxicams-induced photodermatitis, all oxicams should be avoided, to elude posible cross-reactions.