Abrupt cessation of smoking can lead to the development of a distinct line of demarcation between the stained nail and the clear nail, physically noting the time that the smoker quit. Studies have also shown an increased prevalence of psoriasis among smokers, especially female smokers. Those smoking 20 or more cigarettes a day had the highest risk of psoriasis. Nicotine causes diminished blood flow in the skin and decreases tissue oxygenation which can prevent normal healing. Surgical patients that smoke have a greater risk of poor wound healing, tissue death, as well as wider, more pronounced scarring.
Male smokers are at higher risk of developing cancer of the penis.
Studies have shown female smokers have an increased risk if cancer of the external genitalia. Researchers also found cigarette smoking to be significantly' associated with anal SCC in both men and women. Oral cancer has been overwhelmingly linked to smoking. Heavy consumption of alcohol acts synergistically with smoking to increase the risk of oral cancer. One study found that a heavy smoker, someone smoking more than 50 packs a year, had a 77.5 times the risk of oral cancer than a nonsmoker.