Definition
A blister on the finger is a change in the level of the skin, which presents itself as a fluid-filled elevation. The blisters can occur in 3 different skin layers. They can be deep and therefore “tight” or superficial and “flabby”.
In the field of dermatology, blisters are among the so-called primary efflorescences, i.e. skin changes that are due to a direct cause. Furthermore, blisters can be further differentiated depending on their size. A blister (lat.
Bulla) which is smaller than 5 mm is called a vesicle. The cause of a blister on the finger can vary greatly. On the one hand, mechanical or chemical stimuli can cause a blister, but on the other hand, blistering skin diseases can also be responsible.
Causes
It is very important to determine the cause of a blister on the finger, as the therapy is designed accordingly. The most common cause is mechanical overstrain of the skin. Above all, a punctual stress at one point of the finger causes certain layers of skin to separate from each other and the resulting gap fills with tissue fluid.
This can occur with any strain on the fingers beyond the usual extent. Be it in everyday life or through sporting activities. In addition to the mechanical component, chemical stimuli or burns can also cause blister formation.
Contact allergies can also manifest themselves in the form of blisters on the fingers. In this case a clarification of the allergens is necessary to avoid them in the future. In addition to the causes mentioned so far, which are rather due to local manipulations and influences, there are also systemically based triggers.
These include a number of blistering skin diseases. If there is any suspicion, a precise diagnosis must be made in order to be able to initiate the appropriate therapy. The clinical picture of “dyshidrosis” can also be behind a blistering of the finger. In this case, however, several small blisters occur characteristically, which are accompanied by severe itching.
Diagnosis
The first step in diagnosing a bladder is a detailed medical history interview. Here the doctor can obtain important information by explicitly asking about any recent mechanical stress on the affected finger or any known skin diseases or allergies. If, in addition to blistering, symptoms such as burning or itching occur, the diagnosis may be eczema.
A thorough inspection is then necessary. The condition of the bladder should be assessed. Depending on whether the bladder is flabby or tight, the symptoms can be inferred.
In addition, the fluid contained in the bladder should be assessed, i.e. whether it is clear, cloudy, purulent or even bloody. Finally, the number of blisters should also be assessed. Is it a single bubble or are there many small bubbles.
If a blistering skin disease is suspected, special tests must be carried out and an immunohistological, pathological examination must be performed. The detection of antibodies can also be useful. In general, it still has to be assessed whether it is an irritation-free, non-inflamed blister which does not require more specific therapeutic measures but can heal on its own.