OBJECTIVETo investigate the influence of normal saline nasal irrigation with different temperature on allergic rhinitis (AR) and to confirm the appropriate temperature of nasal irrigation.

METHODSSixty patients with AR were randomly divided into 3 groups (according to random number table) and received 15 °C, 25 °C or 40 °C normal saline nasal irrigation respectively, and 20 healthy controls received no treatment. Visual analogue scale ( VAS) was used to assess the symptoms among the control group and the various intervention groups and the enzyme linked immunosorbent assay (ELISA) was applied to detect the contents of histamine, leukotriene C4 (LTC4), house dust mite D1 specific IGE (sIGE) and eosinophil cationic protein (ECP) among the control group and the various intervention groups. GraphPad Prism 5 software was used to analyze the data.

RESULTSThere was no statistical difference between 15 °C normal saline nasal irrigation group and 25 °C normal saline nasal irrigation group. Pre-intervention and post intervention whether is VAS scores of rhinorrhea, sneezing, nasal obstruction and nasal pruritis or in contents of histamine, LTC4, sIgE and ECP showed no difference (all P > 0.05). However, the symptoms of (sneezing VAS score: 3.765 ± 0.291; nasal obstruction VAS score: 3.529 ± 0.365). The difference was significant (t = 4.678, P < 0.001; t = 3.901, P < 0.01). The contents of histamine [ (21.78 ± 0.62) ng/ml] and LTC4 (17.43 ± 0.67 ng/ml) were also decreased after intervention of 40 °C normal saline nasal irrigation [ histamine content: (18.82 ± 0.52) ng/ml; LTC4 content: (13.14 ± 0.59) ng/ml ]. The difference was significant (t = 3.632, P < 0.01; t = 4.79, P < 0.001). Nonetheless, there were no statistical differences in VAS scores of rhinorrhea (t = 2.02, P = 0.051) and nasal pruritis (t = 1.984, P =0.056) and in contents of sIgE (t = 1.891, P = 0.066) and ECP (t = 2.021, P = 0.05). There were statistical differences between the 40 °C group and the 25 °C group normal saline nasal irrigation group in symptoms of sneezing (t = 2.060, P = 0.048) and nasal obstruction (t = 2.1053, P = 0.048). and inflammatory factors of histamine (t = 2.078, P = 0.045) and LTC4 (t = 2.149, P = 0.038). In symptoms of rhinorrhea and nasal pruritis and local production of sIgE and ECP, there was no statistical difference (all P > 0.05).

CONCLUSION40 °C normal saline nasal irrigation can improve the symptoms of sneezing and nasal obstruction and can alleviate the local levels of inflammatory factors like histamine and LTC4 in AR patients, and is the appropriate irrigation temperature.