To investigate the efficacy of modified Dingchuan Decoction in treating children with cough variant asthma (CVA) of phlegm-heat accumulation in the lung syndrome and its effects on eosinophil (EOS) and serum amyloid A (SAA) levels.

From June 2021 to June 2024, a total of 104 children diagnosed with CVA (Phlegm-Heat Accumulation in the Lung Syndrome) who received treatment at Huai'an Traditional Chinese Medicine Hospital were randomly assigned into two groups: an observation group comprising 52 cases and a control group also consisting of 52 cases, with the assignment process conducted using a random number table method. The control group received a therapeutic regimen consisting of budesonide suspension administered via inhalation, complemented by montelukast sodium chewable tablets taken orally, while the observation group was treated with modified Dingchuan Decoction. After 1 week of treatment, traditional Chinese medicine syndrome scores, inflammatory factors (EOS and SAA), immune indicators (CD3⁺, CD4⁺, and CD8⁺), pulmonary function indices (FEV1 and FVC), clinical efficacy, and adverse reactions were compared between the two groups.

After treatment, traditional Chinese medicine syndrome scores, EOS, SAA, and CD8⁺ levels in the observation group and the control group decreased, with the observation group showing lower levels than the control group (P < 0.05). The CD3⁺, CD4⁺, FEV1, and FVC levels in both groups increased compared to before treatment (P <0.05). The observation group had higher levels than the control group (P <0.05). The treatment efficacy rate in the observation group was higher than that in the control group (P <0.05). During the treatment, no severe adverse reactions were observed in either group.

The modified Dingchuan Decoction is effective in treating children with CVA, which helps to suppress airway inflammation and improve the anti asthmatic effect of children, with good safety.