Why do rashes with rough spots occur under the armpits?

Hi doctor,

My daughter is 5 years old. A few weeks ago, rashes started appearing under her armpits. It is like one bigger wound with rough dots. It is not getting any better and is spreading now. There are also some dots on the tummy, but it is primarily present under the armpits. It is the first time she has had a rash. It is winter in our region, and we always wear a lot of clothes. Is this condition related to that, or is it atopic eczema, fungus, stress, or allergies? She had regular flu and winter diseases during the last weeks; otherwise, she is fine. Among her friends, many had corona, but still, now she has not gotten corona.

Hi doctor,

Thanks for the reply. That seems like a very accurate diagnosis. It came during a cold period here in our region. I have forwarded your answer to my regular doctor (who is not a dermatologist) and asked if I need to see a specialist. My doctor prescribed Fusidic acid Hydrocortisone acetate cream the other day, and we just started using it. Is that enough, or do you think the tablets are necessary? Do I have to consult a dermatologist in our area? I am worried whether it will get worse, spread internally, and lead to sepsis. I have read somewhere that although not common, systemic bacterial infections and eczema herpeticum can be life-threatening. How serious is this condition exactly? Kindly help.