Synonyms in a broader sense
Mechanical skin damage, clavus, callus, bladder, callus, corn
Definition
The bladder is a raised cavity filled with fluid that lies directly under the cornea or in deeper skin layers. Various skin irritations can lead to the formation of blisters: skin allergies, sunburn, burns, herpes infections, insect bites, pemphigus diseases (autoimmune diseases). Pressure, rubbing or chafing can lead to blistering in sports. A distinction is made between marching blisters, pressure blisters and rubbing blisters. Repeated mechanical damage leads to callus formation with the formation of a central keratotic (from horn) plug, = cornstalk (so-called clavus), which resembles a foreign body and painfully presses on the surface with a thorn reaching into the subcutaneous tissue.
Causes and symptoms
Blisters on the foot are usually caused by tight-fitting shoes, especially new sports shoes or hiking boots often cause problems. Friction and pressure cause the body to react with a blister to cushion the affected area. Predisposed are ankles, toes, heels, places where socks wrinkle and the area around the sole of the foot warts.
A warm and humid climate favours blisters on the foot. Long, unaccustomed (e.g. sporting) strains can often cause blisters. At first the area becomes sore, painful and appears reddened.
Later, fluid-filled blisters appear. Open wounds, which can also bleed, are particularly unpleasant. Infections often occur here.
They should be covered and padded, preferably with special blister plasters. If the blisters threaten to burst on their own, one can consider puncturing them. As the wound continues to heal, it scabs and slowly heals.
To prevent blisters on the foot, it is important to wear correctly fitting shoes and not to wear new shoes too long. You should also make sure that your feet are kept dry and in case of pressure points you should use tape or plaster as a preventive measure. In case of punctual strain on the toenails, repeated bruising (so-called tennis toe) or even bloody nail loosening can occur (see: Bruising under the nail).
Blisters on the hand can have various causes. They also include mechanical stress, such as heavy gardening work, which is often associated with tools, instruments or sports equipment (e.g. tennis, golf etc.). In addition, blisters can also be a reaction to chemical allergens.
The blisters are rather small, the hands are very red and the blisters itch and wet. This is also called allergic contact dermatitis or dyshidrosis. Especially people who already suffer from other allergies are often affected.
These so-called atopic people also react allergic to otherwise harmless substances. Many different substances trigger contact eczema, such as nickel and substances in creams and ointments. Occupationally, hairdressers, painters and cleaners are therefore often affected.
Contact with the allergenic substances should be avoided at all costs. Some medications can also trigger eczema as a side effect. After the blisters have healed, the skin heals scaly.
If the blisters are caused by mechanical irritation, gloves should be worn for future work. Puncturing the blisters is painful and the wounds can often become inflamed. If possible, the blisters should therefore be covered. Blisters and painful calluses can of course also occur in other places with unusual or increased strain, e.g. behind the ears or on the bridge of the nose due to pressure from glasses (so-called granuloma fisuratum).
