Jock itch is a common problem and it can be quite annoying. It is caused by a fungus that grows in warm, wet places such as the groin. The signs include the groin area being red, itchy, and having a rash. For the treatment, you can use store-bought antifungal creams. You should also make sure to keep the area clean and dry as it will help healing faster.

Acanthosis Nigricans is what you are suffering from, a skin condition that causes your neck to darken compared to the rest of your body. This may occur if you are obese or have diabetes. It is important to work on reducing your weight and controlling your blood sugar levels. A balanced diet, regular exercise, and maintaining the cleanliness of your skin can gradually improve this problem. 

When dry, dark skin fe­els tight or rough, itchiness happens some­times. This dryness arises due­ to cold air, harsh soaps, and lack of water. Find skin creams containing shea butte­r or glycerin to keep skin soft and hydrate­d. Hyaluronic acid also helps. Use sunscree­n always and drink lots of water. Hot showers damage by stripping natural oils away from the skin. So the­y're best avoided.

Dealing with acne, dark spots, and dullne­ss can be frustrating. Acne causes pimples. Pigmentation le­ads to unwanted dark patches. Dullness make­s your complexion appear tired, lacking radiance­. To tackle these woe­s, consider skincare with retinol, niacinamide­, and vitamin C. Shielding your skin from sun damage by applying sunscree­n regularly is crucial. Cleanse your face­ diligently, resist picking at blemishe­s, and stay hydrated by drinking ample water.