It is safe to use a friend's derma roller after disinfection if it has been sprayed with alcohol. HIV is a sexual infection; sharing needles is one of the transmitter. A sterilized roller is thus no cause of fear or stress if someone else has got HIV. Such sterilized tools do not risk transmitting HIV.

Slow hair growth is due to reasons such as lack of vitamins, demanding work, or hereditary influences. If you notice that your hair is no longer growing as fast as it used to, you should try eating a balanced diet full of vitamins and minerals, for example, vitamin D and iron. Besides, find some time for yourself to practice relaxation techniques to de-stress. 

It seems that the burn is rather extensive and does not heal well. I would suggest early consultation with a dermatologist or burn specialist. Do not use any more cream and let the wound dry. It is essential to keep the wound well cleaned, dressed and treated. Seek medical help at the earliest.

The boil-like structure could be a symptom of an infection. Pain and irritation while urinating are the most frequent. These include antibiotics or antifungal creams to help with the infection. The area should be kept clean and dry for a quicker recovery process. Drink lots of water and do not use strong soaps on the wound. 

Popped pimple­s can leave scars. These­ scars can make you feel unhappy. Pimple­ scars show up when popped or picked. To he­lp with these scars, try using creams or oils with ingre­dients that fade scars. Howeve­r, remember it might take­ time for scars to disappear complete­ly. 

You may be dealing with a cold sore that’s popped up on your top lip, making it hurt and itch. That’s probably because of a virus called herpes simplex. Acyclovir is a good choice for getting some relief from this. Just use it like they tell you to. Doing this can help you heal better faster and help lessen the signs and symptoms. 

According to what you mentioned, you may have developed cheek pain without any redness or feeling cold. This can a condition known as trigeminal neuralgia which causes sudden and severe facial pains. Make sure you rest, use warm moist clothes on your face then take over-the-counter painkillers. However, if it does not improve or gets worse then you need to see a doctor for further advice.

A small circular bald spot on the scalp after popping a pimple is not uncommon, but if the area is sensitive and hair is falling out, please see a dermatologist to rule out infection or other underlying conditions.

Razor bumps in the bikini area are a common cause for concern. Injuries to follicles that occur through shaving are usually behind these bumps. They are typically red, itchy, and with small bumps. When ketoconazole cream does not help, another alternative is the use of a mild hydrocortisone cream that can help to control inflammation. Put on some lotion to the part all the time so it stays moisturized.