There are many different reasons why a person might suffer from itchy blisters. Some are relatively minor skin conditions, such as a mild allergic reaction, dry skin, or a bug bite. In other cases, these blisters can be the sign of a serious medical condition such as shingles, cellulitis, or even a sexually transmitted disease.
Blisters can vary in appearance, and some may be accompanied by a rash or other skin conditions. Itchy blisters with a rash are often a symptom of an allergic reaction called dermatitis. Many different things can cause dermatitis, from poison ivy to common household chemicals such as detergents and cleaning solutions.
If the itchy blisters are accompanied by a rash and a fever or other flu-like symptoms, then they can be a sign of shingles, measles, or chickenpox. All three of these can become serious medical problems and in extreme cases can even be fatal. The itchy rash and blisters that accompany these conditions are usually painful and irritating. Some may even break and bleed if scratched. In these cases medical attention should be sought immediately.
Some types of blisters are signs of conditions related to skin diseases like rosacea and psorasis. Antibiotics can usually treat rosacea, but additional treatment, such as creams and ointments, is usually needed to help alleviate blisters and other systems that are related to psorasis. Both are chronic conditions that need continued treatment in order to be properly controlled.
Some small itchy blisters may be the sign of an infection. If the areas around the blisters are extremely tender, sensitive, and warm to the touch, then they may be a sign of cellultis, boils, or folluculitis. These need to be cleaned regularly to help reduce the risk of the infection spreading. In some cases, antibiotics and other medication may be prescribed to kill the infection.
Insect bites can also be a cause of blisters that itch. If the redness from the bite doesn't spread and no signs of infection are found, blisters caused from bites are typically harmless. Ointment can be used in these cases to help dull the itchiness.
Blisters that itch may also be the sign of a sexually transmitted disease (STD). Both genital warts and herpes are STDs that show themselves as blisters, usually on the genitals or around the mouth. The viruses that cause both these conditions cannot be cured, but medication and other treatments exist to help reduce the severity of blister outbreaks.