Allergy to dexchlorpheniramine. Study of a case.

INTRODUCTION: Dexchlorpheniramine (DH) is a classical or first generation antihistamine belonging to the ethanolamine group. Adverse effects related to these antihistamines are frequent, but the hypersensitivity reactions described in the literature since 1940 are exceptional. We report the case of a 32-year-old woman who experienced two episodes of akathisia secondary to intravenous (i.v.) dexchlorpheniramine administration for a possible hypersensitivity reaction to local anesthetics. MATERIAL AND METHODS: Allergological study consisted of the following tests: skin prick tests with routine allergens, with a negative result; skin prick and intradermal tests with local anesthetics and DH, with a positive result to DH in the intradermal skin test (+ +); serum specific IgE, which was within normal levels; histamine release test with DH with a negative result, and the basophil activation test (BAT) with local anesthetics and DH, which was positive for DH and weakly positive to Lidocaine. CONCLUSION: BAT is proving to be a highly useful tool in the field of drug allergy, with a higher sensitivity and specificity than other in vitro tests. Because it avoids the need for provocation tests, this is especially important in drug-induced allergic reactions in which in vivo tests are repeatedly negative despite a clear clinical history.

Allergy to dexchlorpheniramine. Study of a case

Introduction: Dexchlorpheniramine (DH) is a classical or first generation antihistamine belonging to the ethanolamine group. Adverse effects related to these antihistamines are frequent, but the hypersensitivity reactions described in the literature since 1940 are exceptional. We report the case of a 32-year-old woman who experienced two episodes of acathisia secondary to intravenous (i.v.) dexchlorpheniramine administration for a possible hypersensitivity reaction to local anesthetics. Material and methods: Allergological study consisted of the following tests: skin prick tests with routine allergens, with a negative result; skin prick and intradermal tests with local anesthetics and DH, with a positive result to DH in the intradermal skin test (+ +); serum specific IgE, which was within normal levels; histamine release test with DH with a negative result, and the basophil activation test (BAT) with local anesthetics and DH, which was positive for DH and weakly positive to Lidocaine®. Conclusion: BAT is proving to be a highly useful tool in the field of drug allergy, with a higher sensitivity and specificity than other in vitro tests. Because it avoids the need for provocation tests, this is especially important in drug-induced allergic reactions in which in vivo tests are repeatedly negative despite a clear clinical history (AU)

Introducción: La Dexclorfeniramina es un antihistamínico clásico o de 1.ª generación perteneciente al grupo químico de las Etanolaminas. Son frecuentes los efectos adversos relacionados con estos antihistamínicos pero las reacciones de hipersensibilidad descritas en la literatura desde 1940 son excepcionales. Presentamos a una mujer de 32 años que tuvo en dos ocasiones un cuadro de acatisia secundario a la administración de dexclorfeniramina endovenosa (e.v.) para tratar una posible reacción de hipersensibilidad a anestésicos locales. Material y métodos: En el estudio alergológico realizado se efectuaron pruebas cutáneas (Prick) a los alergenos habituales con resultado negativo; pruebas cutáneas a medicamentos (Prick e intradermo) con anestésicos locales y dexclorfeniramina con resultado positivo en intradermo a dexclorfeniramina + + ; IgE sérica total que resultó dentro de la normalidad, Test de Liberación de Histamina (TLH) a dexclorfeniramina con resultado negativo y Test de Activación de Basófilos (TAB) frente a anestésicos locales y dexclorfeniramina con resultado positivo para dexclorfeniramina y levemente positivo para Lidocaína. Conclusión: El TAB está demostrando ser una herramienta muy útil en el campo de la alergia a medicamentos, donde cuenta con una sensibilidad y especificidad superior a otras técnicas in vitro, siendo especialmente importante en aquellas reacciones alérgicas medicamentosas en donde a pesar de los datos anamnésicos claros, las pruebas in vivo son repetidamente negativas, evitando así la realización de pruebas de provocación (AU)