¿Por qué hay lesiones en la piel de mi pene?

I can see that scratching you due to a street dog can be a worrying issue for you. From your information, the scratch is not too deep, which may mean there is a low chance of infection. Watch out for any redness, swelling, or warmth around the area. First of all, wash the scratch using soap and water and then apply the antiseptic cream to the area to avoid any further infection. Watch the scratch for a few days, and if you spot any of the infection signs that are getting worse, like more pain, redness, or pus formation, it is better to go to a doctor. 

It looks like you have bad case of ringworm which did not respond to the OTC medicines. I suggest that as soon as possible you see a dermatologist who specializes in fungal infections. They may give you oral antifungal medicine and topical treatment to improve the result. Seek urgent medical care since untreated ringworm can cause problems.
 

You have jock itch, which is a skin condition that grows a fungus on your skin in hot and damp regions such as the inner thighs. The list includes itching, blackening of the skin as well as rashes. Treatment of the ailment entails you having to purchase antifungal creams. This illness is one of those that often recur. Keep your skin clean and dry after training to prevent it from flaring up again.

You have chicken pox accompanied by a slight cold that can be uncomfortable. Chickenpox is the cause of red spots on your skin and itchiness, while a cold can lead to a cough or sneezing. To help with the itchiness, you can take oatmeal baths and use calamine lotion. For the cold drinking warm fluids and resting should be the first. Ensure that besides drinking water, you also get enough sleep in order to allow your body to naturally combat the viruses responsible for these symptoms.

If it has turned slightly yellow, it may be a minor infection. Using Boroline is fine at the moment. When it is discharging clear liquid, then it is healing. Do not pick it, keep it clean, and look for any redness or increased pain. It will get better in about a week. 

Its natural to experience discoloration in skin especially after a blister or wound has occurred. color changes during the healing process. It could be due to hyperpigmentation which is the increased production of melanin in that area. This can result in a bruise-like appearance.

Vitamin B12 and vitamin D deficiency lead to hair loss. It is advised that you see a dermatologist and an endocrinologist for a thorough examination and treatment.