Differential diagnosis of reddened and chapped nasolabial folds: 1. Head and face psoriasis. The damage is scattered into flakes, the boundary is clear, the scales are very thick, the touch is uneven, the hair does not fall off, the short hair is gathered and becomes a bundle, the heavy damage can be connected into a large area, expanding to the anterior hairline, invading the forehead for several centimeters. Scrape off the scales have film phenomenon (that is, scrape off the scales, under which is a red shiny film) and hemorrhagic phenomenon (that is, gently scrape the film can appear scattered small bleeding spots), film phenomenon and hemorrhagic phenomenon is an important feature of psoriasis damage. 2.Rose chaff rash. Predominant in the neck, trunk, limbs proximal, oval-shaped rash, the center is slightly yellow, the edge of the slightly elevated, light red, with white chaff-like scales. At the beginning of a single damage, known as the mother spot; mother spot gradually, the diameter of up to 2 ~ 5cm or larger, sometimes there can be 2 ~ 3 mother spot at the same time, 1 ~ 2 months after the successive emergence of smaller red spots, occurring in the trunk, the long axis of the rash and the same pattern of the skin, generally 4 ~ 6 weeks to subside on their own, do not recur. 3.Tinea corporis. The edge of the damage is elevated and narrow. The boundary is clear, there is a central healed to the surrounding expansion of the ring-shaped damage. Itching is obvious, and patients often have the history of tinea pedis. 4, erythematous aspergillosis. Mainly distributed in the face, neck, chest and back in the middle. Beginning in the face with symmetrical shaped erythema, covered with scales and scabs, the back of the neck and chest and back erythema on the basis of blisters appeared, rupture after the formation of scabs, Niehl’s sign is positive. (i.e. in the blister top pressure, that is visible blister liquid to the surrounding epidermis penetration; pulling the wall of the blister wall of the remnants of the wall, caused by the surrounding epidermis further peeling; more importantly, the appearance of normal skin is also a rubbing that is broken). 5, rosacea-like dermatitis. Does not involve the scalp area. Eyebrows and nasolabial folds is not a good site, more than a long-term history of externally applied hormonal preparations of medication. Occurred in the face is also known as facial seborrheic dermatitis, facial seborrheic dermatitis is often spread from the scalp, the face before the forehead, supraorbital, eyelids, nasolabial folds especially. At the beginning of the affected area redness, iterative corn size papules, its color reddish, for a long time is the fusion, color yellow red, covered with greasy thick crust, such as cream like fat, or Zhenshui yellow sticky, itching more than one, eyebrow hairs are often sparse due to scratching off, nasolabial folds and behind the ears can be cracked.