Symptoms of dermatological diseases, also known as clinical manifestations of dermatological diseases, are an important basis for recognizing and diagnosing dermatological diseases, and are generally divided into conscious symptoms and objective symptoms. Conscious symptoms are the symptoms felt subjectively, which are the way of expression of the nature of dermatological diseases. The main sensations are itching, pain and numbness, followed by foreign body sensation and abnormal response to temperature. Because of individual differences in people, the perception of sensations such as itch and pain varies. Itching is the most common sensory symptom in dermatology, and it is mainly a manifestation of allergic skin diseases and some infectious skin diseases, reflecting the nature of the disease as a result of allergy. Common diseases include various eczema and dermatitis, urticaria and drug rash. In addition some infectious skin diseases such as impetigo and tinea pedis and some malignant tumors such as mycosis fungoides. Pain is the second most common sensory symptom in dermatology, which reflects the nature of the disease as an infectious skin disease, such as: folliculitis, boils, dermatitis, cellulitis, herpes simplex, herpes zoster, and genital herpes. There are also vasculitis, lipofuscinosis, dermatofibromas and smooth muscle tumors. Numbness and diminished or absent sensation to heat and cold are the cutaneous manifestations of leprosy. Objective symptoms are the abnormal cutaneous manifestations of the skin disease, also called lesions or rashes. These lesions are classified as primary or secondary. Clinicians refer to these symptoms, which can be observed or examined, as signs.