Sandy soil dermatitis in medicine refers to frictional mossy rash, usually not caused by fungal infection, its etiology is unknown, mostly related to external stimuli and other factors. Frictional tinea versicolor is a non-specific skin reaction caused by external stimuli, generally not caused by fungal infection, the etiology of which is unclear, and may be related to external stimuli, mechanical friction and other factors. Patients with frictional tinea versicolor have hemispherical or flat papules, which are covered with scales and often densely distributed. This disease has a certain degree of self-limitation, patients should reduce the local friction in daily life, so as not to aggravate the condition. You can use topical glucocorticoid drugs, such as dexamethasone, halomethasone, etc., to play the effect of anti-inflammatory and anti-itch. For patients with frictional mossy rash, it is recommended to go to a regular hospital for examination, and cooperate with doctors to standardize treatment.