hi. thanks for sharing your problem here. your husband got the sunburn but unfortunately it got infected...you should take extra care,,,i will advise to wash the burnt area,keep it clean,apply antibiotic cream with soothing effects like (bacitracine +xylocain), or fucidic acid(better to take pus swab for culture sensitivity) ,,if fever is also present then also to start oral antibiotic like co-amoxiclav ,use some painkiller and anti inflammatory like ibuprofen.also anti allergic like fexofenadine..wash the area multiple time in a day..when the area is healed use sunblock to prevent it from excessive melanin deposition...hope this will work...thanks dr ihsan