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. 

Pigmentation is a condition that can be compared to skin getting a different tone in some areas. It may be caused by environmental factors like the sun, changing hormonal levels, or it is sometimes the skin's natural characteristic. A cream infused with ingredients such as niacinamide or kojic acid would help to lighten the pigmentation. Remember to wear sunscreen every day to improve your skin health.

If the lumps move around easily, they're likely harmless. These lumps might be caused by swollen glands, cysts, or fatty tissue. If there are no changes or issues, just keep an eye on them. However, if they start getting bigger, it's important to see a doctor.

Tetanus disease comes with some toxic dirty cuts that make swallowing very hard as well as stiffness of muscles generally. Such people should ensure the scratch is germs-free by washing it with water and soap and then applying any antiseptic. One should also note that if you have not had any tetanus vaccination within the last ten years, make sure it is done as soon as possible to prevent further infections.

You may have jock itch, a fungal issue­. It makes groin areas red, itchy, rashy, affe­cting the scrotum, and testicles. In warm, moist places le­t it grows. Try drugstore anti-fungal creams. Clean, and dry the­ zone to avoid return. Jock itch thrives whe­n sweaty, warm. Over-the-counte­r creams help clear up the­ fungus rapidly. However, kee­ping areas dry is crucial. That prevents future­ jock itch flare-ups. So cleanliness matte­rs alongside medication.