Your long study hours creates heat and moisture that likely damaged your skin barrier, making it hypersensitive to sweat or stool. Without pain or bleeding, your itching is likely caused by moisture, a fungal infection common in sweaty environments, or idiopathic pruritus, where a scratch itch cycle keeps the skin from healing.
Next Steps
keep the area clean using only lukewarm water, avoiding soaps and harsh rubbing, and ensure it is completely dry with a cool-setting hairdryer after bowel movements. Apply a thin layer of zinc oxide based barrier cream for protection, wear loose cotton underwear, and take standing breaks every hour to reduce pressure and moisture avoid common triggers like caffeine, spicy foods, citrus, and dairy, as these can irritate the area during bowel movements. Most importantly, you must stop scratching, as it creates micro tears that keep the itch cycle going; keep your nails short to prevent accidental damage
Health Tips
Since this has persisted for 2.5 years, you should consult a dermatologist or a proctologist for a formal diagnosis. They can rule out fungal infections or specific skin diseases like psoriasis or eczema