Aims Relapses in childhood nephrotic syndrome (NS) are often precipitated by viral upper respiratory tract infections (URTI). This study was undertaken to ascertain the effect of a short course of low dose corticosteroids during URTI on relapse frequency in patients with steroid sensitive NS who are off corticosteroids.

Method A placebo-controlled crossover trial was conducted on 48 patients with steroid dependant NS who had been off corticosteroids. Patients recruited were into one of two groups. Group A received 5 days of daily prednisolone at 0.5 mg/kg at the onset of an URTI while group B received 5 days of placebo. Both groups were followed up for one year and the URTI induced relapse frequency was noted. A cross over was performed for the next year with group A receiving placebo and group B receiving prednisolone. The student t-test was used to compare continuous variables. The Fishers exact test was used to compare categorical variables.

Of the 48 patients recruited, 33 completed the study. The mean (SD) age at baseline was 12.0 ± 2.4 years for the treatment group and 10.0 ±2.9 years for the placebo group. In the treatment group 113 episodes of URTI led to 11 relapses while in the control group 101 episodes of URTI led to 25 relapses. There was no significant difference between the mean number of URTIs between the treatment and control groups (3.5 ± 1.5 and 3.2 ± 1.4, p = 0.31). The treatment group had a significantly lesser number of relapses compared to the control group (p = 0.014). The majority (65.6%) within the treatment group did not relapse whilst the remaining subjects had a single relapse. In contrast only 40.6% of the control group remained in remission whilst 40.6% suffered from a single relapse and 18.8% had two relapses.

Conclusion Administration of a short course of daily corticosteroids during a presumed URTI significantly reduces the frequency of URTI induced relapses in patients with steroid sensitive NS who are off corticosteroids.