Von Zumbusch psoriasis, also known as acute generalized pustular psoriasis, is a rare type of psoriasis characterized by white, pus-filled blisters (pustules). The pustules are not contagious but are the result of sudden and extreme autoimmune inflammation. It differs from the two other types of pustular psoriasis, which are generally limited to the hands or feet, and is considered far more serious.
Von Zumbusch can develop at any age but predominately affects adults over 50. The outbreak of symptoms, referred to as a flare, may be triggered by any number of things, including medications and stress. Diagnosed by a physical exam and the evaluation of a pus sample, Von Zumbusch almost always requires treatment in a hospital.
Von Zumbusch can appear abruptly on the skin. The symptoms start with widespread areas of reddened skin that become increasingly painful and tender. Within hours, tiny pustules appear, many of which will consolidate into larger blisters. The pustules can easily rupture when scratched or abraded. Fever and fatigue are common.
Within 24 to 48 hours, the pustules will dry up, leaving a glazed and smooth appearance. The affected skin can be extremely itchy and peel away in sheets. This is not only painful but can lead to the rapid loss of moisture and massive dehydration.
Symptoms of severe dehydration can include:
- Extreme thirst
- Dry mouth
- Reduced urination
- Dark-colored urine
- Muscle weakness
- Rapid heart rate
- Rapid, shallow breathing
- Fever and chills
- Leg swelling
According to a 2016 review in the journal Psoriasis, no less than 65% of adults with pustular psoriasis will have had a prior diagnosis of plaque psoriasis. Recurrent flares are not uncommon.
Children rarely get Von Zumbusch psoriasis. When they do, it is often their first psoriatic event and tends to be less severe than what is seen with adults.
As an autoimmune disease, psoriasis is characterized by an immune system gone awry. For reasons poorly understood, the immune system will suddenly regard normal skin cells as harmful and launch an inflammatory attack. This can lead to the accelerated production of skin cells, allowing them to build up one atop the next into dry, scaly lesions known as plaques.
With pustular psoriasis, the autoimmune response is even more severe. Scientists believe that it is caused by a defect in an inflammatory protein known as interleukin. Under normal circumstances, there will be a “matched set” of interleukin molecules, one that promotes inflammation and the other that tempers inflammation.
If one of the two molecules is defective, it can leave inflammation on “high” with no way to turn it off. What results is a massive burst of inflammation that kills many of the white blood cells involved in the autoimmune assault. The dead cells combined with lymph fluid creates what the white, gooey substance recognized as pus.
The underlying mechanisms of psoriasis have yet be identified, but scientists believe that a combination of genetics (that predispose you to the disease) and environmental triggers (that actualize the disease) is involved.
With Von Zumbusch psoriasis, there are certain specific triggers known to incite a flare:
- Emotional stress
- The abrupt discontinuation of corticosteroid drugs
- Medications, including salicylates, lithium, penicillin, interferon, and terbinafine
- Strong, irritating topical medications, such as coal tar or anthralin
- Skin infections, especially Staphylococcus aureus and Streptococcus epidermidis
- Excessive sun exposure
- Hypocalcemia (low blood calcium)
- Pregnancy, most especially during the third trimester
- Bacille Calmette-Guerin (BCG) vaccination for tuberculosis
Despite the plethora of common triggers, most cases of pustular psoriasis are idiopathic, meaning of no known cause.
There are no lab tests or imaging studies that can definitively diagnose psoriasis. The diagnosis of Von Zumbusch starts with a physical examination and a review of your medical history.
Although the appearance of pustules may be a giveaway, the healthcare provider will look for other clues to confirm the suspicion, including a prior history of plaque psoriasis, a family history of autoimmune disease, or recent exposure to specific medications.
Your healthcare provider may also want to obtain a pus sample for evaluation in the lab. Because pustular psoriasis is not caused by an infection, there should be no evidence of a bacteria, virus, or fungus in the sample.
If the results are inconclusive, a differential diagnosis would be performed to differentiate Von Zumbusch psoriasis from other diseases with similar features. These include:
- Dermatitis herpetiformis
- Bacterial septicemia
- Secondary infection of generalized atopic dermatitis or seborrheic dermatitis
- Immunoglobulin A (IgA) pemphigus, an autoimmune blistering disorder
Von Zumbusch psoriasis can be life-threatening and requires immediate medical care. This is most often delivered in a hospital where rehydration and supportive care are provided. The treatment protocol is similar to that of a severe burn.
The aims of treatment are to:
- Prevent fluid loss
- Stabilize the body’s temperature
- Restore the skin’s chemical balance
In addition to intravenous (IV) fluids, topical, oral, or IV antibiotics may be used to prevent secondary infections.
Supportive therapy with cool compresses and saline or oatmeal baths can help soothe the skin and gently remove (debride) dead skin.
To help temper the acute flare, an oral retinoid called Soriatane (acitretin) is commonly prescribed. Retinoids slow the hyperproduction of skin cells and help bring the acute symptoms under control. Severe cases may require immunosuppressant drugs (methotrexate, cyclosporine) or the biologic drug Remicade (infliximab).
Once the acute crisis has passed, psoralen and ultraviolet A (PUVA)—a type of phototherapy—may be used to bring the condition into sustained remission.
There is really no way to prevent Von Zumbusch psoriasis given that so little is known about the underlying causes. With that being said, if you have had a previous flare, you are at risk of recurrence and need to take preventive action. This should include:
- Avoiding known triggers: If you are not sure what they are, keep a diary of any psoriatic symptoms you experience, however minor. This can help pinpoint the conditions or substances you need to avoid.
- Stopping smoking.: Smoking is one of the main risk factors for Von Zumbusch psoriasis. It doesn’t necessarily trigger the disease but appears to increase your risk exponentially.
- Reducing your alcohol intake: This is especially true with non-light beer, which increases the risk of psoriasis in general. If you cannot stop entirely, limit yourself to no more than two to three drinks daily, replacing non-light beer with light beer or wine.
- Avoiding excessive sun exposure: Limit your daily sun exposure to 15 to 20 minutes (the amount that can benefit your skin), and always wear plenty of sunscreen. Avoid tanning beds.
- Managing your stress: Mind-body therapies like meditation, guided imagery, and progressive muscle relaxation (PMR) can help reduce stress and, with it, the risk of flares.