Hi there. It sounds like you have HS as well and I believe my last comment on this thread may help you. Best of luck.
This sounds like hideadentitis supparavita. I have this condition. The cause is unknown. It is incurable but treatment can help. Abscesses can be treated with oral and topical antibiotics, though some need to be lanced. Losing weight helps to reduce the occurrence rate in overweight people. I had to get surgery due to the frequency and severity of the abscesses in my right armpit. The doctors removed my sweat gland and all of the skin that had hair. I have not had any more abscesses in that area since but continue to have them in other areas. Depression is common with the condition due to the painful, embarrassing nature of HS so it is important to monitor her for signs and symptoms. Hope this helps and best of luck.
Hiya, I've been suffering with what sounds like the exact same illness, I also have no idea what it is but I've gone through numerous operations to drain and remove these abscesses.
I normally get these all under my right armpit, but my most recent ones are two under the arm and on the lower half of my back which in turn is stopping me from walking, laying down, sitting down or standing for too long
The pain is excruciating and no doctor seems to know what's wrong with me
I see a specialist on Feb 4th
I'm sorry I can't give any answers, but I just wanted to let you know your sister isn't alone x
She has recurring abscesses. Lifestyle changes may make a difference - like no sugars at all, low carbohydrates, lots of exercise to ideal weight.