Symptoms
The primary feature of bullous pemphigoid is the appearance of large blisters that don't easily rupture when touched. The fluid inside the blisters is usually clear but may contain some blood. The skin around the blisters may appear normal, reddish or darker than usual. Some people with bullous pemphigoid develop an eczema or hive-like rash rather than blisters.
In most cases, the blisters appear on the lower abdomen, groin, upper thighs and arms. Blisters are often located along creases or folds in the skin, such as the skin on the inner side of a joint.
The affected areas of skin can be very itchy. You might also develop blisters or sores in your mouth. If the mucous membranes of your eyes and mouth are primarily where your blisters are concentrated, this type of condition is called mucous membrane pemphigoid. If you develop blisters on your eyes, you're more likely to have scarring. This condition requires prompt diagnosis and treatment.
When to see a doctor
If you develop unexplained blistering â a condition not caused, for example, by a known skin allergy or contact with poison ivy â see your doctor.
Source: http://www.mayoclinic.com