4.1.4 Skin damages caused by protective products
Although the purpose of skin protective products is to protect the skin，repeated or prolonged contact with the protective products may cause skin damages at the same time.Overall，the PPE is short in poor air permeability and will rub and oppress the skin，and the protective agent has a certain degree of absorbability and sensitization.Although the protective products used in different industries are made from various materials，the skin problems caused by protective products used for the same part of the body are basically similar.
1.Skin pressure injuries
PPE（e.g.，helmets，masks，gas masks，and goggles）often cause skin damage to the face and ears.Such equipment needs to be tightly attached to the skin surface，which compresses the skin at the fixed site for many hours and may result in device-related pressure injuries.The factors contributing to device-related pressure injuries include poor local blood circulation，and ischemia and hypoxia of tissue.The accumulation on the inside of the mask of a large amount of water vapor exhaled from the mouth and nose and skin evaporation，keep the facial skin in a moist environment for a long period.This softens and impregnates the skin，and reduces the ability of the stratum corneum to resist external pressure and shear forces.Thus，the skin is prone to indentations（Figure 4-2）.In addition，the friction between the PPE and the skin enhances the development of erythema，blisters，or ulcers，along with pain and even secondary infection.
2.Folliculitis
Wearing a helmet or hat for a long time may lead to folliculitis.The scalp is rich in hair follicles，sebaceous glands，and sweat glands，and therefore secretes large amounts of oil and sweat.Due to the poor permeability of hair，hats，and helmets，the sweat and oil secreted by the scalp mix together and remain on the skin surface of the head，consequently blocking the pores and making it easier for folliculitis to develop when bacteria colonize.Aggravation of this inflammation may lead to skin lesions such as pustules，boils，seborrheic dermatitis，and secondary fungal infection.
3.Skin fungal and bacterial infections
To completely isolate the wearer from harmful substances in the environment，gloves and protective clothing are mostly made of waterproof materials with poor air permeability，such as rubber and plastic.If the skin is left in an air-impermeable environment for long periods，the sweat evaporation is decreased，and the skin is prone to impregnation，eczema，and sweat herpes.Furthermore，the hot and humid environment is conducive to fungal reproduction.In particular，the vulval，medial thigh，and perianal areas are predilection sites for skin inflammation and secondary bacterial and fungal infections due to excretion irritation and repeated friction during walking.(https://www.daowen.com)
4.Eczema
In addition to wearing gloves，hand hygiene is also essential for chemical and biological protection.However，repeated cleaning can lead to a reduction of grease on the skin surface，thus damaging the normal skin barrier.As a result，the skin shows symptoms such as dryness and itching，as well as hand and foot eczema.
5.Contact dermatitis
Repeated contact with irritants such as disinfectants and gloves can cause contact dermatitis with erythema，pimples，exudation，or erosion.One study found that 52％of medical staff with hand eczema wash their hands more than 10 times per day.Long-term disinfectant use also influences the microbiota and changes the immune microenvironment on the skin surface，resulting in conditions such as eczema，fungal infection，bacterial infection，and allergic dermatitis.Irritation of sweat and sunscreen may also cause an allergic skin reaction.
6.Acne
The materials used to make explosion-proof clothing，stab-resistant clothing，and other protective clothing are relatively hard，which may cause device-related pressure injuries due to friction between the clothing edge and the skin.Industrial and medical protective clothing have requirements for tightness，which keeps the skin over the whole body in a humid environment and makes it prone to impregnation.People with large amounts of sebaceous gland secretions are likely to develop acne in areas rich in sebaceous glands（e.g.，chest and back），due to the pores being blocked by sweat and sebum.At the same time，inorganic sunscreen is also easy to clog pores and cause acne.