The chest area has a lot of brown patches, considering that it may be caused by fungal infections, allergies or pigmentation spots, it is recommended to go to the hospital for a detailed examination in a timely manner, and then according to the specific causes of the symptomatic treatment. 1. Fungal infection: If the skin on the chest is infected by Malassezia, it may cause lichen planus, and if the treatment is not timely, it will lead to skin pigmentation resulting in brown patches. 2. Allergy: if the chest is exposed to allergens, it may cause allergic dermatitis, first of all, avoid allergens, and then you can use chlorpheniramine, loratadine and other drugs for treatment. 3. Pigmented spots: pigmented spots can also occur on the chest, related to genetic factors, sun exposure, etc., which can be manifested as brown spots. It is recommended to consult the dermatology department of the hospital for the above symptoms. Usually pay more attention to maintain personal hygiene and cleanliness, try to avoid contact with allergens, and at the same time pay attention to diet, try to take less spicy and stimulating food, and develop a healthy and good eating habits.