You may have a fungus infection in your groin. It may result in scratching and irritation of the affected areas. I suggest you go to a dermatologist who can diagnose and cure your disease.
 

PIGMENTATION can have many causes. See a dermatologist. Avoid the sun. Use sunscreen. Use skin lightening creams carefully...

If you have dark spots on your face, which could be caused by your sebaceous glands being blocked or the skin gathering too much pigment, they probably are. Face cleaning and protection from the sun are the two main prevention methods for infinite spots. You want a cream that includes retinol, A, not to forget vitamin C, to ensure it will lighten the color in time. 

This may happen due to many reasons, such as dry skin, eczema or allergies and contact dermatitis. Itch sensations may also be heightened at night due to the natural circadian rhythm of the body. It is advised to apply a hypoallergenic moisturizer before going to bed, which can mitigate symptoms of dry skin. It is possible to manage allergic reactions by identifying potential triggers such as certain soaps or fabrics and avoiding them. If chronic or aggravating, it is so recommended to consult a dermatologist for an in-depth evaluation and tailored treatment options targeting the true cause of nighttime scratch.

You may have something referred to as a perianal abscess. When bacteria infect a tiny gland around the anus, this can cause a painful lump. Soaking in warm water may help relieve discomfort. Don’t squeeze or pop it—try to keep the area clean instead. If it becomes worse or doesn’t get better, you should go see your doctor for more help.

Dandruff is caused by yeast overgrowth on scalp. Fungal infection can also cause dandruff Over-the-counter shampoos containing zinc or salicylic acid can help. Antifungal shampoos can treat fungal infections. Consult a doctor if symptoms persist. 

It is possible that you are suffering from a skin condition called eczema. Eczema is a chronic condition that causes the skin to become irritated, red, and itchy. If the itching is severe or does not improve with over-the-counter treatments, you should see a dermatologist for further evaluation and treatment. A dermatologist can help diagnose the problem and provide you with the best treatment plan. They may suggest topical steroids, oral medications, light therapy, or other treatments to help control your symptoms.