Your GP may rightly have suspected a “fungal” type of acne from your history, or a condition called Pityrosporum folliculitis.
As you’ve described, it’s commonly associated with sweat and acne appearing on your back. With Pityrosporum follicultis, you may also notice some lighter spots (or hypopigmentation) on your back, a condition known as tinea versicolor (click link for images).
Clotrimazole topical (an anti-fungal) is one of the correct treatments.
Selsun (available over the pharmacy in most pharmacies in Singapore) is another topical treatment for Pityrosporum follicultis which you could try. Zinc Pyrithione is one of the ingredients in Selsun.
Dr Colin’s advice still stands – visit a doctor to get the diagnosis and treatment right.
Cheers
