You have a fungal infection in your private area. Sometimes it can be due to sweat, tight clothing, or not drying properly after a shower. The main symptom is the itch and the redness. This can be treated with antifungal cream. Keep the area clean and dry. Loose-fitting cotton underwear and not scratching the area will make it better.

Itchy, rashy skin down there­ is no fun, especially in the he­at. This could be jock itch - a fungal thing. Nature's reme­dies like nee­m, turmeric, and aloe may help. Stay away from tight clothe­s. Keep the are­a dry and airy. Eat healthy foods. 

New scratches have added to old ones recently, so it's important to watch for signs of infection like redness, swelling, or pus. Clean the wound with soap and water, and monitor it closely. If you notice any of these symptoms, see a doctor right away.

It is possible that the black vertical line on the boy's thumb nail is a result of a melanonychia striata, which is a linear nail melanin pigmentation. It is relatively common in children and is generally harmless. However, it is important to have it evaluated by a doctor, especially if it is growing, to rule out any underlying medical conditions.

You are having alopecia areata a disease that causes bald spots on the beard. The situation is not life-threatening but it can be quite annoying. In this case, a topical steroid ointment application that diminishes the inflammation in those areas will be helpful. Furthermore, the use of biotin supplements is likely to help hair regrowth as well.