Pustular Psoriasis

Pustular Psoriasis Overview

Pustular psoriasis is an uncommon form of psoriasis. People with pustular psoriasis have clearly defined, raised bumps on the skin that are filled with pus (pustules). The skin under and around these bumps is red. Large portions of your skin may redden.

Pustular psoriasis. Note the clearly defined, raised bumps on the skin that are filled with pus (pustules). The skin under and around these bumps is red.

The skin changes you may notice before, during, or after an episode of pustular psoriasis may be similar to those of regular psoriasis. People with the usual skin symptoms of psoriasis have patches of raised skin with scales.  
 
Pustular psoriasis is classified into one of several types, depending on your symptoms. Your symptoms may be sudden and severe (acute), long term (chronic), or somewhere in between (subacute). The generalized type affects your whole body with more than just skin symptoms. A generalized type with acute symptoms, fever, and a toxic reaction in your tissues is called the von Zumbusch type. A ring-shaped (annular, or circinate) type has also been described. It is usually subacute or chronic, and people with this type do not usually have symptoms aside from the skin symptoms. Pustules may be localized to the palms and soles (palmoplantar pustulosis). The least common type is the juvenile, or infantile type, which occurs in children.
 
Pustular psoriasis is not common. In Japan, only about 7.46 people per 1,000,000 have pustular psoriasis. Pustular psoriasis affects all races. In adults, it affects men and women equally. In children, it affects boys somewhat more often than girls. The average age of people with pustular psoriasis is 50 years. Children aged 2-10 years can be affected, but this is rare.

Pustular Psoriasis Causes

Eruptive pustules have been associated with the following causes: 

• Taking systemic steroids (steroid medications given by mouth or by injection) and then discontinuing them
  
  
• Various drugs, including the following:
  
  
  • Salicylates, compounds made from salicylic acid, often used to treat pain and fever
    
    
  • Iodine, a topical antiseptic
    
    
  • Lithium or trazodone, antidepressants
    
    
  • Phenylbutazone or oxyphenbutazone, nonsteroidal anti-inflammatory drugs (NSAIDs)
    
    
  • Penicillin, an antibiotic
    
    
  • Hydroxychloroquine, an antimalarial drug
    
    
  • Calcipotriol, a vitamin-D derivative
    
    
  • Interferon alfa and recombinant interferon-beta injections, chemotherapeutic agents
  
  
• Strong, irritating topical solutions (creams or ointments applied to the skin), including tar, anthralin, steroids under occlusion, and zinc pyrithione in shampoo
  
  
• Infections
  
  
• Pregnancy
  
  
• Sunlight or phototherapy
  
  
• Cholestatic jaundice (a yellowish staining of the skin and eyes, caused by bile)
  
  
• Hypocalcemia (abnormally low levels of calcium in the blood)

 In many people, the trigger is never identified.

Pustular Psoriasis Symptoms

In the generalized type, the skin is initially fiery red and tender. You may have symptoms such as headache, fever, chills, joint pain, a feeling of general discomfort or uneasiness, decreased appetite, and nausea. Within hours, you may see clusters of pustules.
 
The most common places these pustules appear are the anal and genital area and bends and folds in your skin. Pustules may appear on the face, but this is unusual. Pustules can appear on the tongue, which may make it difficult to swallow. They can also occur under your nails and cause your nails to come off.
 
Within a day, the pustules fuse together and form "lakes" of pus that dry and peel off in sheets. The skin underneath is a smooth reddish surface, on which new pustules can appear. These episodes of pustules appearing, fusing and peeling, and reappearing can last for days to weeks. They can make you uncomfortable and exhausted. In 2-3 months, a phase involving hair loss can occur.  
 
Once the pustules improve, most of your other symptoms (such as headache and fever) will usually disappear. However, in some people, the skin may remain bright red, and skin symptoms of nonpustular psoriasis may continue.
 
The ring-shaped type is more common in young children. This type tends to be subacute or chronic, and the symptoms are less severe than in the generalized type. Ring-shaped plaques (elevated areas) appear and are often recurrent. Pustules may appear at the edges of the ring. These areas of skin symptoms appear mostly on the trunk but also on the arms and legs. The edges expand, and the center heals. Other symptoms are either absent or mild.
 
The juvenile, or infantile, type of pustular psoriasis is usually mild. Other symptoms besides skin symptoms are seldom present. The condition often resolves on its own.

Pustular psoriasis of the palms and soles is usually chronic and may be associated with bone or joint inflammation. The palms or soles are red with white or yellow pustules.