Lichen Planus - Causes

The exact cause of lichen planus is not well understood till date, but various theories exist on what can trigger this condition. Some of the commonly cited reasons include the following:

• An allergic or immune reaction to a medication or other substance has been strongly associated as the cause for this condition. It is considered to be an auto-immune disease, in which the body's protective cells attack the body's own tissues mistaking them to be foreign in nature.
• Certain cases have been linked to infections such as hepatitis C.
• Intake of few drugs such as those containing arsenic, bismuth, gold quinacrine or quinidine (anti-malarial drug) non-steroidal anti-inflammatory drugs, can cause a reaction similar to the lichen planus rash.
• Chemicals such as those used in the development of colour photographs can also produce a similar rash.
• Intense and prolonged emotional stress due to grief, sadness, anxiety, etc., can trigger an abnormal functioning of the immune system that can lead to lichen planus.
• Heredity is a common enough cause of lichen planus.
• Amalgam dental fillings may trigger allergic reactions, giving rise to oral lesions of lichen planus.