Sjögren syndrome or Sjögrens syndrome (SjS, SS) is a long-term autoimmune disease that affects the bodys moisture-producing (lacrimal and salivary) glands, and often seriously affects other organ systems, such as the lungs, kidneys, and nervous system. Primary symptoms are dryness (dry mouth and dry eyes), pain and fatigue. Other symptoms can include dry skin, vaginal dryness, a chronic cough, numbness in the arms and legs, feeling tired, muscle and joint pains, and thyroid problems. Those affected are also at an increased risk (15%) of lymphoma.While the exact cause is unclear, it is believed to involve a combination of genetics and an environmental trigger such as exposure to a virus or bacterium. It can occur independently of other health problems (primary Sjögrens syndrome) or as a result of another connective tissue disorder (secondary Sjögrens syndrome). Sjögrens syndrome may be associated with other autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) or systemic sclerosis. The inflammation that results progressively damages the glands. Diagnosis is by biopsy of moisture-producing glands and blood tests for specific antibodies. On biopsy there are typically lymphocytes within the glands.While Sjögrens syndrome is one of the most common auto-immune diseases, it has no specific and non-invasive diagnostic tests and treatment is directed at managing the persons symptoms. For dry eyes, artificial tears, medications to reduce inflammation, punctal plugs, or surgery to shut the tear ducts may be tried. For a dry mouth, chewing gum (preferably sugar-free), sipping water, or a saliva substitute may be used.
Some chemical warfare agents, known as blister agents or vesicants, cause large, painful blisters wherever they contact skin; an example is mustard gas. Blood blister
A blood blister usually forms when a minute blood vessel close to 
the surface of the skin ruptures (breaks), and blood leaks into a tear between the layers of skin. This can happen if the skin is crushed, pinched or aggressively squeezed. Medical conditions
There are also a number of medical conditions that cause blisters. The most common are chickenpox, herpes, impetigo, and a form of eczema called dyshidrosis. Other, much rarer conditions that cause blisters include:

Bullous pemphigoid: a skin disease that causes large, tightly filled blisters to develop, usually affecting people over the age of 60. Pemphigus: a serious skin disease in which blisters develop if pressure is applied to the skin; the blisters burst easily, leaving raw areas that can become infected. Dermatitis herpetiformis: a skin disease that causes intensely itchy blisters, usually on the elbows, knees, back and buttocks. The blisters usually develop in patches of the same shape and size on both sides of the body. Chronic bullous dermatosis: a disease that causes clusters of blisters on the face, mouth or genitals. Cutaneous radiation syndrome
Epidermolysis bullosa

Pathophysiology
Friction blisters
Friction blisters are caused by excess shear stress between the bottom and surface of the skin and the body. The strata of skin around the stratum spinosum are most susceptible to shear. As the stratum spinosum tears away from the connecting tissues below, plasma from the cells diffuses out.