The first question to answer is "why am I losing hair in my hair line?" It is essential that you establish a diagnosis first, then you will have a road map to fix the problem. You may need a complete workup (via a board-certified dermatologist with expertise in hair loss) of your hair loss + maybe even a scalp biopsy. Once all the information is in, a comprehensive treatment plan can be formulated that specifically addresses the cause of the hair loss. I have many patients that have similar hair loss to you and do quite well with the proper treatment.
Side effects from finasteride are pretty uncommon in my experience, but they do occur. The most common side effect I see is decreased sex drive, which almost always goes back to normal when the drug is discontinued. Management of a side effect depends on how severe and persistent it is. Sometimes decreasing the dose can be helpful, sometimes not. There is risk with every drug we put in our bodies and sometimes it is best to stop the drug altogether and opt for a drug-free therapy.
From the photo, I doubt it is a type of scarring alopecia, but it is hard to be sure. Trichoscopy would be a good option. Sometimes in my clinic a trichoscopy yields more answers than scalp biopsies. Please keep in mind that the person who performed your scalp biopsy may have not have sampled the area that would produce a correct diagnosis. This is called sampling error and is very common with scalp biopsies. Other information would be helpful such as medical history, family history and of course a physical exam by a specialist dermatologist.
This is actually a fairly common occurrence in my experience. Sometimes the cyst compresses and "kills off" the hair follicles deep in the skin. Removing the cyst may lead to hair growth in the area, but it is not guaranteed.
Systemic absorption of topical dutasteride solution has not been validated and is unknown. That being said, there may be some that does in fact get in the bloodstream. That is why I would never recommend a pregnant or lactating person use dutasteride in any vehicle. Injectable dutasteride is a highly uncertain treatment for some types of hair loss, and is best not used at all. In conclusion, the likelihood of developing gynecomastia with topically applied or injected dutasteride is theoretically possible but highly unlikely.
