Hi
Itching in the perineal region is a common problem. This occurs because of reasons starting from occlusion, sweating, to detergents in clothes, or to fungal infections etc.
In your case the photographs rule out fungal infection.
It could be due to simple maceration to sweat or to stress.
I suggest
1. Use anti fungal powders like absorb or powders which lowers the sweat like low sweat powder liberally in the day.
2. Use minimally potent corticosteroid like hydrocortisone cream (Efficort) at night.
3. Take one anti histamine at night like Levo cetrizine at bed time.
4. Reduce tension and avoid stress.
5. rinse your inner wears in plain water after washing to get rid of any detergents remaining.
I hope you will recover from this simple problem.
Good day
Prasad PVS

---