Sensitization to common ragweed in southern Bavaria: clinical and geographical risk factors in atopic patients.

BACKGROUND: Sensitization to common ragweed (Ambrosia artemisiifolia) is associated with a variety of risk factors, which are incompletely defined. Our aim was to evaluate the association of a variety of clinical, geographical and demographical variables with ragweed sensitization and also to determine its frequency in southern Bavaria. METHODS: In this cross-sectional multicentre study, we enrolled 977 patients with a documented or suspected atopic disease or food allergy. Data were collected on aeroallergen sensitization, age, sex, type and history of allergic disease, place of residence and potential local ragweed exposure. For this last variable, county ragweed cover was taken as a surrogate variable. Relative rates were calculated with multiple additive logistic regression models. Randomly selected patients with ragweed sensitization had a conjunctival provocation test. RESULTS: According to skin prick tests, 190 patients (19.5%) were sensitized to ragweed. The frequency of this finding increased significantly with a rising number of additional sensitizations. Other less important predictors for a ragweed sensitization were male gender, mugwort sensitization, food allergy and a maximum of complaints in September or October. County of residence, extent of local ragweed cover or type of residential area were without relevance. Of 48 sensitized patients, 26 (54.2%) had a positive conjunctival provocation test. DISCUSSION: Patients with multiple sensitizations may be more readily sensitized to a new aeroallergen. Local geographic or environmental conditions are presumably of minor importance for becoming sensitized to ragweed. The frequency of ragweed allergy among sensitized patients might be high.

Immediate-type hypersensitivity to succinylated corticosteroids.

BACKGROUND: Despite their frequent use, systemic corticosteroids have rarely elicited immediate-type reactions. OBJECTIVE: We report two male patients, aged 26 and 70 years, respectively, with severe immediate-type hypersensitivity secondary to the administration of corticosteroids esterified with succinate. METHODS: Skin tests, basophil activation tests and challenge tests were performed for diagnostic evaluation. RESULTS: In both patients, immediate-type skin test reactions were found to methylprednisolone sodium hemisuccinate (MSH) and prednisolone sodium hemisuccinate (PSH). In contrast, nonsuccinylated corticosteroids (including methylprednisolone and prednisolone in one patient) yielded no test reactions. Basophils from one patient exhibited a stimulated expression of the activation marker CD63 upon in vitro incubation with PSH or hydrocortisone sodium succinate, but not with hydrocortisone. Skin tests and basophil activation tests were negative in controls. One patient was challenged with the incriminated drugs. He developed flush, conjunctivitis, tachycardia and dyspnea 2 min after injection of MSH, and dyspnea shortly after intravenous administration of PSH. Oral and intravenous challenge tests with nonsuccinylated corticosteroids were tolerated well by both patients. CONCLUSIONS: These case reports should alert clinicians to rare, but severe immediate-type reactions to corticosteroids, related to the succinate moiety in our patients. In case of allergic reactions to corticosteroids, it is mandatory to identify the causative agent and find safe alternatives.