Smoking damages nearly every organ in the body. Whilst most people are familiar of its association with lung cancer, stroke and heart disease, it also has profound effects on the body’s largest organ – skin.
Unlike damage to your heart or lungs, the effects on skin are often outwardly visible for people to see. Not only is smoking related to the development of certain skin disorders, it is a major culprit in premature ageing of the skin. The aim of this article is to review the cutaneous effects of smoking.
Premature Skin Ageing
The link between smoking and wrinkles has been known for many years. Smoking is an independent risk factor for developing wrinkles. Women seem to be more susceptible to this than their male counterparts. Commonly, this manifests as fine lines around the eyes (“crow’s feet) and mouth (smoker’s lines) at an earlier age than non-smokers.
Aside from early wrinkling, other facial features have been described in smokers. These include atrophy (or thinning) of the skin, plethora (facial redness), and prominence of the underlying bony contours of the face.
The mechanism by which smoking causes early facial ageing is poorly understood but several hypotheses have been proposed. These include:
- Increase in certain enzymes known as matrix metalloproteinases which promote breakdown of collagen and elastic fibres in the skin
- Increase in atoms or molecules known as free radicals that accumulate causing physiological decline in the skin’s structure and function
- Phototoxicity of tobacco smoke – smoke becomes more toxic under the influence of ultraviolet radiation
- Vasoconstriction (narrowing of blood vessels) reduces blood flow to the skin and can cause subsequent changes to elastin and collagen in the connective tissue.
Poor Wound Healing
There are a large number of studies that demonstrate smoking will delay wound healing – this includes injury and wounds created by surgery. There are higher rates of wound infection, decreased wound strength, skin graft failure, necrosis (death of tissue), and blood clot formation.
The reasons for delayed wound healing are likely to be multi-factorial:
- Nicotine causes vasoconstriction and a 30-40% decrease in blood flow soon after inhaling cigarette smoke. This results in reduced delivery of much needed oxygen and other nutrients needed for the skin to regenerate.
- Nicotine makes certain blood cells (platelets) more “sticky” resulting in the formation of tiny blood clots. These can block small blood vessels preventing oxygen reaching wound tissue.
- Tobacco inhibits the activity of cells known as fibroblasts that are responsible for producing collagen. Reduced collagen synthesis can result due to alterations in normal inflammatory processes that occur during wound healing.
- Smoking can delay the formation of new blood vessels within a wound by inhibiting important growth factors e.g. endothelial growth factor.
Smoking and Skin Cancer
Smokers are at higher risk of developing a type of skin cancer known as squamous cell carcinoma (SCC). Even individuals that only smoke a few cigarettes a day remain at risk of this.
It is thought that tobacco found in smoke acts to suppress the immune system allowing cancer cells to evade recognition. Whilst SCC is easily treated if found early, it does have the potential to metastasise (or spread) to other parts of the body and can potentially be life-threatening.
Inflammatory Skin Disorders
Psoriasis is a relatively common inflammatory disorder of the skin, which results in dry, scalp patches on the body. Smokers have a higher risk of developing this condition compared to non-smokers. They are also more likely to have severe and more extensive disease that is less likely to respond successfully to treatment.
Nicotine is thought to directly affect the immune system, potentially triggering psoriasis in those individuals that may already have an underlying tendency towards developing this condition. It binds to skin cells known as keratinocytes, promoting their cell division and turnover.
This is a chronic, painful condition that results in painful boil-like swellings and abscesses under the skin that can often discharge and leave residual scarring. It commonly affects the armpits and groin area. Hidradenitis is found more frequently in smokers. Whilst the reasons for this are not entirely clear, there is a suggestion that nicotine acts on the immune system and skin cells leading to blockage and rupture of hair follicles.
Discoid lupus erythematosus is an auto-immune skin condition where scaly, red patches often appear in sun-exposed sites. The areas can often clear but leave behind scarring. This occurs at least ten times more commonly in smokers compared to non-smokers. Treatment of this condition with antimalarial and other drugs has also shown to be less effective in smokers.
Smoking and Viral Infections of the Skin
Genital warts are caused by the Human Papilloma Virus (HPV). Smoking enhances the risk of developing genital warts. This may be related to the immunosuppressive effects of nicotine. Smokers also have a higher risk of developing wart virus related cancers including cancer of the vulva, anus, and penis.
The skin, like all other organs in the body, is susceptible to the damage caused by cigarette smoke. This article has aimed to raise awareness of some of the more common cutaneous manifestations of smoking and the skin, but there are many more associations. If you are a smoker, it may be time to consider kicking the habit and seek appropriate help if needed. This will benefit all the organs of your body – skin included.