Dear sir / mam I am suffering from dandruff so ihv using head and shoulders shampoo  only since one year ,my dandruff reduced completely. Since one month  again the dandruff came back although using head and shoulders shampoo. It is itching more when i sweat or apply oil. If i apply oil i keep it one day and next day i do shampooing. After hair wash i m getting yellow flakes in scalp.(attached photo).I hv seen some redness on my scalp . Feeling some wetness while scratching. If apply oil i m getting soft bump ( only at night)on back of scalp which  is going in the morning and after shampoo. I am attaching photos .. plzz help me🙏 weather it is dandruff or psoriasis . Which shampoo i hv to use..