Sed as levocetirizine-induced fixed drug eruption which was confirmed by patch test. She has crossreactions with other piperazine derivatives like cetirizine and hydroxyzine. We advisable that the individuals steer clear of taking these antihistamines. Fexofenadine might be an TGF alpha/TGFA, Human (CHO) option drug with out adverse reaction to patient.N O OLorantadineFexofenadine, (R)-typeFig. 3. Structures of anti-histamine; piperazine derivatives and piperidine derivatives. Pictures were extracted from web-site (en.wikipedia. org).DISCUSSIONLevocetirizine is the single Transthyretin/TTR, Human (147a.a, HEK293, His) R-isomer of cetirizine dihydrochloride, and has twice of the affinity for the H1-receptor compared to cetirizine [9]. The chemical structures were shown in Fig. three. Levocetirizine was noted as protected and helpful therapy for allergic illness for instance allergic rhinitis and chronic urticaria [9]. There was a few reports of piperazine antihistamine induced delayed hypersensitivity reaction [2-4, 6, 7]. One case-series was reported that hydroxyzine induced fixed drug eruption around the penis in four youngsters [3]. Rechallenges had been carried out and lead to the exact same drug eruption [3]. In 2002, Assou e et al. [2] reported that the hydroxyzine induced exactly the same morphologic cutaneous eruption in the same website which cetirizine had induced drug eruption before. Interestingly, two drugs are piperazine antihistamines. In 2007, Mariana et al reported one particular case of fixed drug eruption to cetirizine [4]. The results of patch test with cetirizine, levocetirizine and hydroxyzine which had been all piperazine antihistamines had been positive. These outcomes could possibly be evidences apallergy.orgthat delayed type antihistamine induced hypersensitivity showed cross-reactions among similar chemical structures. A number of situations of instant hypersensitivity reactions have been also reported [6, 10, 11]. In 2006, Gonz ez de Olano et al. [10] reported a cetirizine-induced acute urticaria which was confirmed by oral provocation test, while the skin prick test was unfavorable. In 2009, a case of cetirizine induced anaphylaxis was reported [12]. Severe breathlessness, urticarial eruption, loss of consciousness and hypotension had been developed within 15 min right after oral ingestion of cetirizine, and recovered right after epinephrine injection. That was the very first exposure for the patient, and also the mechanism of anaphylaxis induced by cetirizine was unclear [12]. Within the first-generation antihistamines, hydroxyzine, buclizine, cyclizine and meclizine belong to piperazines [1]. Within the second generation antihistamines, cetirizine and levocetirizine belong to piperazines [1]. A zatadine, c yproheptadine, diphennylpyraline and ketotifen belong to piperidines because the first-generation antihistamines, and astemizole, desloratadine, ebastine, fexofenadine, levocabastine, loratadine, mizolastine, olopatadine and terfenadine belong to piperidine as the secondgeneration antihistamines [1]. Inside the present case, the patient hasdx.doi.org/10.5415/apallergy.2013.three.four.Asia PacificallergyKim MY, et al.a levocetirizine induced fixed drug eruption, and the piperazine derivatives like cetirizine and hydroxyzine showed crossreactions around the patch test. Interestingly, antihistamines that are piperidine derivatives for example ebastine, fexofenadine and loratadine did not show cross-reaction on the patch test. To confirm the safety of alternative candidate drug, oral challenge was performed with fexofenadine. The patient was tolerable even following taking 120 mg fexofenadine for three days, and there was no additi.
