"Disappointing incorrect diagnosis"

Problem: growing spreading large blisters on my 6 year old's kness.

Seen 2 days prior in Teddington minor injuries by a nurse. Diagnosis:"bad reaction". Treatment: leave dressing on for 5 days.

2 days later after further deterioration and spread. South Hams minor injuries: seen by what may have been a nurse again. Diagnosis: " chemical". Treatment: different type dressing.

2 days later: after further worsening seen by own GP at home. Diagnosis: bad bacterial skin infection. Treatment: antibiotics.

I am disappointed with the South Hams diagnosis after already visiting another minor injuries unit.