Hi Pranab,
Thanks for the query. 
I completely understand your concern and I hope I am able to help you for the same. 
Looks like your husdand has developed 
cellulitis over the feet.
We can try conservative treatment first but if the condition continues to worsen , then you might need to consult a physician.
Avoid touching it too much.
Avoid using any kind of 
cold dreams or hair oils..as it might increase the lesion
You can start using any topical antibiotic/antiseptic cream(like 
mupirocin cream) over the lesion for 2-3 days
Take some pain killers along for relieving the associated pain and discomfort 
keep foot end elevated esp at night in order to prevent any swelling
Oral antibiotics are required if the cellulitis increases, which a 
dermatologist / physician can examine and suggest
Take care 
Wishing your husband speedy recovery
Dr Geetika Paul