Discoid lupus erythematosus has many harmful effects, such as scarring alopecia, disfigurement, and pain. If it occurs in the mucous membranes of the mouth and lips, there is a risk of developing squamous carcinoma over time. Discoid lupus erythematosus, the cause of which is not yet clear, is associated with immune system disorders and manifests as scattered, well-demarcated discoid red plaques. If the plaques extend to the scalp, irreversible hair loss called scarring alopecia may develop. If the plaques spread to the ears or nose, darkening of the skin or scarring may result in disfigurement, and red patches on the palms and metatarsals may cause pain. Due to the unpredictable and variable nature of discoid lupus erythematosus, the prognosis is poor if the disease involves the kidneys or the nervous system. If it occurs in the oral mucosa, delays in the disease may carry the risk of developing squamous carcinoma. Discoid lupus erythematosus has many dangers, and it is recommended that once diagnosed, patients should go to the rheumatology and dermatology departments of regular hospitals in a timely manner and follow the doctor’s instructions for treatment.