Three-year-old Xiao Qiang is a lively and active little guy. Recently the weather is getting hotter and hotter, the play area of Xiao Qiang gradually extends from indoor to outdoor, in the garden, in the grass, next to the sand pile, always see his happy figure, often fat and tender little hands are covered with his harvest, grass leaves, dirt scraps, sticks …… mother looked at the healthy growing baby, heart bursting with joy and love. On weekends, mommy washes little strong socks, ho! Really dark! It requires mom to use washing powder water to soak first, then soap to rub. Xiao Qiang was so happy to see the tub full of soap bubbles that he also helped his mother wash his socks. It was full of soap suds. I didn’t expect that after two or three days, some skin-colored bumps began to appear on the back of Xiao Qiang’s hands, gradually more and more, and from time to time there was an itching sensation. A week later, the back of his hands became like toad skin, pimples, and before he went to bed at night, his little hands kept scratching around. His mother had no choice but to bring him to the hospital. After detailed medical history and examination, the doctor told mom that it was friction mossy rash. So, what kind of disease is friction mossy rash? Can Qiang’s white and tender hands still come back? Will there be any comorbidities? When and how will it heal? Frictional lichenoid dermatitis, also called or sandy dermatitis, is a localized skin allergy caused by external physical stimuli. Chinese medicine believes that children have damp heat in their bodies, and some children are naturally intolerant of external frictional stimuli, so damp heat in the body battles with external evil and soaks into the skin. The rash is usually caused by frictional stimulation by water, sand, soap, etc., or after crawling on carpets or blankets, and appears on the back of the hands, wrists and other areas susceptible to friction, manifesting as corn-sized skin-colored or red papules that can fuse with each other in a mossy pattern. The number may be large or small. If diffuse, the rash may involve below the elbow fossa, buttocks, ankles and other friction-prone areas. The rash is often sparsely distributed, with a few tendencies to cluster and show general symmetry. The child’s self-perception varies widely, from no obvious itching to more itchy. The duration of the disease is long, usually 6-8 weeks to heal. The incidence is higher in spring when the weather is warmer and children like to play in water and sand. 3-5 years old is the age group with the highest incidence. Some experts believe that it may be associated with viral infections in the spring, but there is no definitive basis to support this. In children who drink less water, eat more seafood, beef and lamb and other allergy-prone foods, the rash may sprout quickly or the existing rash may worsen rapidly. A small number of children can develop self-sensitivity dermatitis (self-sensitive dermatitis) after scratching intensely or after the combination of a cold or consumption of allergenic foods. This is mainly due to excessive scratching and the appearance of a similar rash in other distant parts of the body about 1 week after the initial rash appears, accompanied by a significant itching sensation. It is particularly severe at night. Some children have difficulty sleeping and eating. It may even be manifested as pityriasis rosea-like rash, with oval-shaped rash, fine scales, and long axis parallel to skin lines. However, it is significantly more itchy than pityriasis rosea, without obvious mother spot stage. The disease needs to be distinguished from contact dermatitis, insect bite dermatitis, and papulopapular acrodermatitis in children. Contact dermatitis can occur at all ages and in different seasons. There is a history of exposure to irritants, a well-defined rash, j localized erythema, flushing, swelling and even blistering. There are significant conscious symptoms of itching. Insect bite dermatitis usually has a history of insect bites or outings, localized skin with a windbag-like rash, markedly red and swollen, usually with a small central hemorrhagic spot for the insect sting, accompanied by significant stinging itch. Papular acral dermatitis in children is caused by hepatitis B virus infection, the rash usually starts from the precinct system, generalized as a solid dark red flat papule, can gradually expand to the upper extremities, and finally appear on the face. Blood tests for hepatitis B surface antigen can be positive. So, knowing this, how to treat sandy dermatitis? For children with mild symptoms, they can heal on their own without medication. It usually takes about 2 months. Some of the rashes with pronounced itching can be treated with oral antihistamines, such as cetirizine drops, loratadine syrup, etc. If the rash affects sleep, paracetamol can be added at bedtime, and topical application of topical itch relief with glyburide lotion can be used for a short time under the guidance of a physician to relieve symptoms and reduce comorbidities. For a small number of children with co-occurring autosensitive dermatitis, short-term oral glucocorticoids and combined topical medications are needed under the guidance of a physician, if necessary. At the same time, Chinese herbal medicine can be given to relieve dampness and itching. While treating, care must be taken to avoid re-irritating the local skin and to reduce the intake of allergy-prone foods.