Abstract
Discontinuing antihistamines for patch testing (PT) in allergic contact dermatitis (ACD) is more conventional than evidence based. Data suggests that non-sedating antihistamines do not interfere with PT. Investigating the effects of sedating antihistamines are more relevant as these are recommended for eczema. We aimed to evaluate the effect of chlorpheniramine on PT, to determine the prevalence of nickel sensitization and common sensitizing allergens. An open labeled cohort study was conducted at two dermatology clinics. Patients indicated for PT underwent standard protocol where antihistamines were discontinued. Patients sensitised to nickel were subjected to a second nickel PT while taking chlorpheniramine. Results were evaluated using the North American Contact Dermatitis Research Group (NACDRG) score, a Mexameter measured erythema and pruritus was assessed using a visual analogue score. A total 82 patients were recruited, 28 (34.1%) were sensitised to nickel. The mean age was 40 ± 17.7 years with 22(26.8%) males and 60 (73.2%) females. Indications for PT included suspected ACD (57.3%), hand and feet eczema (34.1%) and severe eczema with suspected superimposed ACD (6.1%). The commonest sensitizing allergens were methyldibromoglutaronitrile (40.2%) nickel sulphate (34.1%), potassium dichromate (29.3%) and formaldehyde (24.4%). A second PT was performed on 23 patients. There was no difference in the NACDRG score with chlorpheniramine or without chlorpheniramine (p=0.968). Pruritus score was reduced by 1.39 ± 2.9, p=0.031 with chlorpheniramine. The degree of erythema was 611.46 ± 21.59 with chlorpheniramine versus 613.87 ± 27.5 without chlorpheniramine, p=0.671. Chlorpheniramine did not affect PT based on clinical and objective scorings. It has the additional benefit of reducing test-induced itch.
Keywords :
allergic contact dermatitis,
antihistamine,
patch test,
Abstrak
Pemberhentian antihistamin untuk ujian tampalan (PT) dalam dermatitis alahan sentuhan (ACD) adalah lebih bersifat konvensional berbanding berasaskan bukti. Data menunjukkan bahawa antihistamin tanpa kesan mengantuk tidak mengganggu PT. Kajian ke atas kesan antihistamin tanpa kesan mengantuk adalah lebih relevan kerana ianya disyorkan untuk ekzema. Dalam kajian ini kami menentukan kesan chlorpheniramine pada PT, menentukan prevalens sensitif terhadap nikel dan alergen yang lazim. Kajian kohort label terbuka dijalankan
di dua klinik dermatologi. Pesakit yang berindikasi untuk PT menjalani protokol standard PT tanpa antihistamin. Pesakit sensitif nikel menjalani PT kedua sambil mengambil chlorpheniramine. PT dinilai menggunakan skor North American Contact Dermatitis Research Group (NACDRG). Kemerahan dan gejala gatal yang diukur dengan Mexameter dinilai menggunakan skor analog visual. Sejumlah 82 pesakit menyertai kajian ini, 28 (34.1%) adalah sensitif nikel. Purata umur adalah 40 ± 17.7 tahun dengan 22 (26.8%) orang lelaki, 60 (73.2%) perempuan. Indikasi untuk PT termasuk disyaki ACD (57.3%), ekzema tangan dan kaki (34.1%) dan ekzema tahap teruk yang disyaki mengalami ACD (6.1%). Alergen paling lazim adalah methyldibromoglutaronitrile (40.2%) diikuti oleh nikel sulfat (34.1%), kalium dikromat (29.3%) dan formaldehid (24.4%). Dua puluh tiga pesakit sensitif nikel menjalani PT kedua. Tidak ada perbezaan dalam skor NACDRG dengan Chlorpheniramine atau tanpa chlorpheniramine (p=0.968). Gejala gatal telah dikurangkan sebanyak 1.39 ± 2.9, p=0.031 dengan chlorpheniramine. Tahap kemerahan adalah 611.46 ± 21.59 dengan chlorpheniramine berbanding 613.87 ± 27.5 tanpa chlorpheniramine, p=0.671. Chlorpheniramine tidak menjejaskan PT berdasarkan skor klinikal dan objektif. Ia mempunyai manfaat dalam mengurangkan gatal disebabkan oleh PT.
Kata Kunci :
antihistamin,
dermatitis alahan sentuhan,
ujian patch,
Correspondance Address
Adawiyah Jamil. Department of Medicine, Faculty of
Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000
Cheras, Kuala Lumpur, Malaysia. Tel: +603-91456074 E-mail: adda_jamil@yahoo.com
