You are in: eMedicine Specialties > Dermatology > PAPULOSQUAMOUS DISEASES Psoriasis, PustularArticle Last Updated: Jan 16, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Elma D Baron, MD, Assistant Professor of Dermatology, Case Western Reserve University, University Hospitals of Cleveland; Director of Skin Study Center, University Hospitals Research Institute; Acting Chief of Dermatology, Veterans Affairs Medical Center, Cleveland Elma D Baron is a member of the following medical societies: American Academy of Dermatology, American Society for Photobiology, Photomedicine Society, and Society for Investigative Dermatology Coauthor(s): Charles R Taylor, MD, Assistant Professor of Dermatology, Harvard Medical School; Director of Phototherapy Unit, Department of Dermatology, Massachusetts General Hospital Editors: Mark G Lebwohl, MD, Chairman, Department of Dermatology, Mount Sinai School of Medicine; David F Butler, MD, Professor of Dermatology, Texas A&M University College of Medicine; Director, Division of Dermatology, Scott and White Clinic; Director Dermatology Residency Training Program, Scott and White Clinic; Christen M Mowad, MD, Assistant Professor, Department of Dermatology, Geisinger Medical Center; Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University; William D James, MD, Paul R Gross Professor of Dermatology, University of Pennsylvania School of Medicine; Vice-Chair, Program Director, Department of Dermatology, University of Pennsylvania Health System Author and Editor Disclosure Synonyms and related keywords: pustular psoriasis INTRODUCTIONSection 2 of 11
  BackgroundPustular psoriasis is an uncommon form of psoriasis consisting of widespread pustules on an erythematous background (see Media File 1). Pustular psoriasis may result in an erythroderma. Cutaneous lesions characteristic of psoriasis vulgaris may be present before, during, or after an acute pustular episode. Generally, pustular psoriasis may be classified into several types depending on the clinical course, which may be acute, subacute, or chronic. The acute generalized type accompanied by fever and toxicity also is termed the von Zumbusch variant. An annular or circinate type that tends to run a subacute or chronic course with less systemic manifestations also has been described. In addition, a juvenile or infantile type is seen that is the least common. PathophysiologyEnhanced polymorphonuclear leukocyte (PMNL) chemotaxis is much more pronounced in pustular psoriasis than in psoriasis vulgaris. This observation has been attributed to either an intrinsic PMNL defect or to the presence of chemoattractants in the psoriatic epidermis. Although the principal stimulus that triggers the phenomenon of massive PMNL migration from the vasculature to the epidermis is unknown, cytokines elaborated by keratinocytes are believed to aid the process. Electron microscopic studies have shown the presence of basal keratinocyte herniations. These are cytoplasmic processes from basal keratinocytes that protrude into the dermis through gaps in the basal lamina in lesions of pustular psoriasis. These herniations mostly are clustered over collections of neutrophils in the dermis. This finding suggests an increased production of neutrophilic proteolytic enzymes in the dermis of these patients. Immunohistochemical methods have determined the involvement of some of these proteases and their inhibitors in the development of pustulation. Elastase is a proteolytic enzyme released by PMNLs during the process of extravasation and migration through the dermoepidermal junction. An epidermal elastase inhibitor, termed skin-derived antileukoproteinase, was found expressed in psoriatic skin prior to influx of PMNLs and to disappear when the composition of the infiltrate changed. This finding was not confirmed by other studies. Additional studies investigating other potential mechanisms have shown decreased natural killer cell activity in generalized pustular psoriasis. An increased incidence of HLA-B27 also has been found among patients with pustular psoriasis. This haplotype is seen in psoriasis patients with peripheral arthritis, as well as in patients with ankylosing spondylitis and Reiter disease. FrequencyUnited StatesPustular psoriasis is uncommon in the United States. InternationalThe prevalence of pustular psoriasis in Japan is 7.46 cases per 1 million people. Mortality/MorbidityThe generalized pustular psoriasis of von Zumbusch may be lethal if proper supportive measures are not taken during the acute phase. RacePustular psoriasis affects all races. Sex
Age
CLINICALSection 3 of 11
HistoryIn the generalized type, skin initially becomes fiery red and tender. The patient experiences constitutional signs and symptoms, such as headache, fever, chills, arthralgia, malaise, anorexia, and nausea. Within hours, clusters of nonfollicular, superficial 2- to 3-mm pustules may appear in a generalized pattern. The most common sites of involvement are the flexural and anogenital areas. Less often, facial lesions occur. Pustules may occur on the tongue and subungually, resulting in dysphagia and nail shedding, respectively. These pustules coalesce within 1 day to form lakes of pus that dry and desquamate in sheets, leaving behind a smooth erythematous surface on which new crops of pustules may appear. These episodes of pustulation may occur for days to weeks, thereby causing the patient severe discomfort and exhaustion. A telogen effluvium type of hair loss may develop in 2-3 months. Upon remission of the pustular component, most systemic symptoms disappear; however, the patient may be in an erythrodermic state or may have residual lesions of psoriasis vulgaris. The circinate or annular type predominates in infancy. This subtype tends to run a more subacute or chronic course, with less severe manifestations. Often, recurrent episodes of annular or circinate erythematous plaques are seen, with pustules on the periphery. These lesions primarily appear over the trunk but also involve the extremities. They undergo peripheral expansion and central healing. Other systemic signs and symptoms are either absent or mild. The juvenile/infantile type of pustular psoriasis typically has a benign course. Systemic involvement is not common, and spontaneous remissions occur frequently. PhysicalThe patient appears frightened, often tachypneic, tachycardic, and febrile. The oropharyngeal mucosa may be hyperemic, and a geographic tongue or fissured tongue may be appreciated. The skin shows a generalized or patchy erythema studded with interfollicular pustules that may have an annular or nonspecific configuration. Flexural and anogenital accentuation may be present. The lesions may appear on the trunk, extremities, and rarely, on the face. Pustulation also occurs on the nailbeds, resulting in onychodystrophy, onycholysis, and defluvium unguium. Scaling may be observed, especially in areas that already have undergone pustulation. The rest of the physical examination depends on complications in other organ systems, such as the cardiovascular system. CausesThe following have reportedly triggered an eruption:
DIFFERENTIALSSection 4 of 11
Subcorneal Pustular Dermatosis
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| Drug Name | Acitretin (Soriatane) |
|---|---|
| Description | Retinoic acid analog, similar to etretinate and isotretinoin. Etretinate is primary metabolite and acitretin has demonstrated clinical effects similar to those seen with etretinate. Mechanism of action is unknown. More effective when used in conjunction with PUVA. |
| Adult Dose | 0.2-0.5 mg/kg PO qd over several wk; alternatively, 25 or 50 mg/d PO initially given as single dose with main meal; 25-50 mg/d PO after initial response to treatment; terminate therapy when lesions have resolved sufficiently |
| Pediatric Dose | Not established |
| Contraindications | Documented hypersensitivity; pregnancy, concomitant vitamin A, significant liver disease |
| Interactions | Coadministration with methotrexate increases risk of hepatotoxicity; concomitant use with tetracycline or minocycline increases risk of pseudotumor cerebri; ethanol induces formation of etretinate, which has much longer half-life; acitretin interferes with contraceptive effect of microdosed progestin "minipill" preparations; concomitant use of vitamin A increases risk of additive toxicity |
| Pregnancy | X - Contraindicated; benefit does not outweigh risk |
| Precautions | Do not use in severe obesity; women of childbearing age must be capable of complying with effective contraceptive measures; recommended that contraception be continued for at least 3 y after treatment with acitretin ends; etretinate may form from acitretin, which takes approximately 2-3 y to clear; perform AST, ALT, and LDH tests prior to initiation of acitretin therapy at 1- to 2-wk intervals until stable and thereafter at intervals as clinically indicated |
| Drug Name | Isotretinoin (Accutane) |
|---|---|
| Description | Oral agent that treats serious dermatologic conditions. Synthetic 13-cis isomer of the naturally occurring tretinoin (trans-retinoic acid). Both agents are structurally related to vitamin A. Has been used to treat pustular psoriasis. |
| Adult Dose | 1 mg/kg PO qd or bid |
| Pediatric Dose | Not established |
| Contraindications | Documented hypersensitivity |
| Interactions | Toxicity may occur with vitamin A coadministration; pseudotumor cerebri or papilledema may occur when coadministered with tetracyclines; acitretin may reduce plasma levels of carbamazepine |
| Pregnancy | X - Contraindicated in pregnancy |
| Precautions | May decrease night vision; may be associated with development of hepatitis; occasional exaggerated healing response of acne lesions (excessive granulation with crusting) may occur; patients with diabetes may experience problems in controlling blood sugar; avoid excessive exposure to UV light or sunlight |
Regulate cell growth and differentiation.
| Drug Name | Methotrexate (Folex, Rheumatrex) |
|---|---|
| Description | Antimetabolite that inhibits dihydrofolate reductase, thereby hindering DNA synthesis and cell reproduction. Satisfactory response seen in 3-6 wk following administration. Adjust dose gradually to attain satisfactory response. Fever, toxicity, and pustulation may decrease within 24-48 h, but erythroderma usually persists; may take several weeks to work well. |
| Adult Dose | 0.2-0.4 mg/kg PO/IM/wk divided into 3 parts q12h over 36 h qwk or as single weekly dose; alternatively, 10-25 mg/wk PO/IM or 2.5-7.5 mg PO q12h for 3 doses/wk |
| Pediatric Dose | Not established |
| Contraindications | Documented hypersensitivity; alcoholism; hepatic insufficiency; documented immunodeficiency syndromes; preexisting blood dyscrasias (eg, bone marrow hypoplasia, leukopenia, thrombocytopenia, significant anemia); renal insufficiency |
| Interactions | Oral aminoglycosides may decrease absorption and blood levels of concurrent oral MTX; charcoal lowers MTX levels; coadministration with etretinate may increase hepatotoxicity of MTX; folic acid or its derivatives contained in some vitamins may decrease response to MTX; coadministration with NSAIDs may be fatal; indomethacin and phenylbutazone can increase MTX plasma levels; may decrease phenytoin serum levels; probenecid, salicylates, procarbazine, and sulfonamides, including TMP-SMZ, may increase effects and toxicity of MTX; may increase plasma levels of thiopurines |
| Pregnancy | D - Unsafe in pregnancy |
| Precautions | Overdose may result in widespread skin erosions, ulceration, and toxic epidermal necrolysislike manifestations, as well as bone marrow suppression; with long-term use, hepatic fibrosis can occur, therefore, periodic liver biopsies are recommended; monitor CBC counts qmo and liver and renal function q1-3 mo during therapy (monitor more frequently during initial dosing, dose adjustments, or if risk of elevated levels [eg, dehydration]); has toxic effects on hematologic, renal, GI, pulmonary, and neurologic systems; discontinue if significant drop in blood counts occurs |
| Drug Name | Cyclosporine (Sandimmune, Neoral) |
|---|---|
| Description | Demonstrated to be helpful in a variety of skin disorders, especially psoriasis. Cyclic polypeptide that suppresses some humoral immunity and, to a greater extent, cell-mediated immune reactions, such as delayed hypersensitivity, allograft rejection, experimental allergic encephalomyelitis, and graft-vs-host disease for a variety of organs. In children and adults, base dosing on ideal body weight. |
| Adult Dose | 2.5-5 mg/kg/d PO divided bid |
| Pediatric Dose | 1-3 mg/kg/d PO bid; not to exceed 5-7 mg/kg/d |
| Contraindications | Documented hypersensitivity; uncontrolled hypertension or malignancies; do not administer concomitantly with PUVA or UV-B radiation in psoriasis since it may increase risk of cancer |
| Interactions | Carbamazepine, phenytoin, isoniazid, rifampin, and phenobarbital may decrease cyclosporine concentrations; azithromycin, itraconazole, nicardipine, ketoconazole, fluconazole, erythromycin, verapamil, grapefruit juice, diltiazem, aminoglycosides, acyclovir, amphotericin B, and clarithromycin may increase cyclosporine toxicity; acute renal failure, rhabdomyolysis, myositis, and myalgias increase when taken concurrently with lovastatin |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Evaluate renal and liver functions often by measuring BUN, serum creatinine, serum bilirubin, and liver enzymes; may increase risk of infection and lymphoma; reserve IV use only for those who cannot take PO; increased carcinogenicity in patients on methotrexate, PUVA, coal tar, or anthralin therapy; renal dysfunction; hypertension |
| Media file 1: Note the clearly defined, raised bumps on the skin that are filled with pus (pustules). The skin under and around these bumps is reddish. Courtesy of Hon Pak, MD. | |
 | View Full Size Image | Media type: Photo |
| Media file 2: Palmoplantar pustular psoriasis, a type of pustular psoriasis that appears on the palms of the hands or the soles of the feet. Courtesy of Hon Pak, MD. | |
 | View Full Size Image | Media type: Photo |
Article Last Updated: Jan 16, 2007
