Index
This is a generalized eruptive form of psoriasis accompanied by fever and toxicity. It is a medical emergency that requires urgent admission to the hospital.
Acute erythema is seen as a rapid spread of multiple sterile pustules on the body, concentrated in the push-ups, genital areas, and fingertips.
Generalized pustular psoriasis must be distinguished from a localized form of pustular psoriasis known as palmoplantar pustulosis (PPP).
Pustular psoriasis epidemiology
It is a rare condition, precise prevalence figures for the UK are not available. The prevalence is 7 people per 1 million in Japan. The average age of those affected is 50 years, but the range is wide.
Causes
Among the most common causes we find:
- Sunlight or phototherapy.
- Cholestatic jaundice .
- Hypocalcemia .
- No cause is identified in many patients.
Symptoms of pustular psoriasis
- The skin becomes very red and tender.
- Multiple small clusters of pustules appear (2-3 mm), these yellowish pustules develop on an erythematous background and can quickly spread in a generalized pattern.
- In about 24 hours, the pustules coalesce, dry and flake off. Other pustule cultures can appear for days, leaving the patient uncomfortable and exhausted.
- The flexural and anogenital regions are the most commonly affected. Facial injuries are less common.
- Pustules can occur on the tongue and under the nails, causing dysphagia and nail loss, respectively.
- Patients are generally systemically ill with symptoms such as headache, fever, chills, arthralgia , malaise, anorexia, and nausea.
- On examination, there may be a rapid respiratory rate, tachycardia, and pyrexia suggesting a toxic state.
- The tongue is dry and cracked.
- As the pustules are treated, most systemic symptoms subside, but the patient may be left with erythroderma or residual lesions from common psoriasis.
While children and infants can develop generalized pustular psoriasis in the adult form, a circinate or annular type is more common, tending to have a subacute / chronic course and be more benign:
- There are recurrent episodes of erythematous annular or circinate plaques, with pustules on the periphery.
- They are mostly on the trunk but also involve the extremities.
- They expand peripherally while healing in the center.
- Systemic symptoms are mild or absent.
- Spontaneous remissions are common.
Differential diagnosis
- Drug eruptions.
- Septicemia.
- Typical increase in white blood cells with a marked increase in neutrophils and a drop in lymphocytes.
- Elevated inflammatory markers.
- Hypoalbuminemia.
- LFT abnormals.
- Abnormal parameters of kidney function due to acute kidney injury or tubular necrosis.
- There is no microbial growth from pustule and blood cultures.
Treatment
Go urgently to the hospital as it can be a life threatening condition.
Immediate treatments are:
- Intensive nursing and supportive therapy with attention to hydration, fluid balance, nutrition, and temperature regulation.
- Topical compresses and saline or oatmeal baths help soothe and debride affected areas.
There is very limited evidence regarding the efficacy of different systemic therapies alone or in combination, in part due to the rarity of the disease.
Treatment can be challenging, with troublesome side effects or lack of response.
In fact, case reports have implicated some of the agents used to treat generalized pustular psoriasis with aggravation / induction of the condition, for example:
- Ciclosporin.
- Etanercept e infliximab.
Specific medications include:
- Oral retinoids, usually acitretin.
- Systemic corticosteroids.
- Methotrexate .
- Colchicina.
- Biologic therapies, for example, infliximab, etanercept, ustekinumab, adalimumab, and anakinra.
- Psoralen combined with ultraviolet A (UVA) light treatment (PUVA).
PUVA cannot be tolerated in the early stage, except in children who tend to experience milder illness. Once the patient is stable, usually after several days of acitretin, they can be started.
Complications
- A secondary bacterial infection of the skin can occur.
- Hair loss with telogen effluvium is possible.
- The nails will be lost with subungual involvement.
- The hypoalbuminemia may result from loss of plasma proteins in tissues.
- Reduced circulating volume can cause renal tubular necrosis.
- Poor circulation and general toxicity can cause liver damage.
- Poor absorption and malnutrition.
- Death from heart failure , sepsis, or acute respiratory distress syndrome.
Forecast
- Older patients with the von Zumbusch type variant have a worse prognosis.
- Children tend to have a good prognosis unless it is a secondary infection. The protosis is better when the pustular psoriasis was preceded by a common chronic psoriasis.
