Pustular Psoriasis

J Cutan Pathol 2008; 35: 169–173. Abstract quote

The differential diagnosis of psoriasis affecting palmoplantar skin might be troublesome because of the anatomic properties of this region. Both palmoplantar psoriasis and eczematous dermatitis of this skin area share similar histologic features. The punch biopsies from 17 patients with psoriasis and 25 with eczematous dermatitis were evaluated, blind to the clinical diagnosis. Vertically situated multiple foci of parakeratosis, alternating with orthokeratosis, were the only statistically significant feature in the differential diagnosis of palmoplantar psoriasis [76.5% (13/17), p = 0.005]. In contrast, multiple foci of parakeratosis [70.6% (12/17)], loss of granular layer at least in focal areas [41.2% (7/17)], presence of neutrophils at the summits of parakeratosis [4% (1/17)], presence of neutrophils and/or plasma in the parakeratotoic foci [94.1% (16/17) and 11.8% (2/17)], psoriasiform epidermal hyperplasia [88.2% (15/17)], spongiosis restricted to the lower parts of the epidermis [47.1% (8/17)], dyskeratotic cells [82.4% (14/17)], thinning of suprapapillary plate [58.8% (10/17)], edema of the papillary dermis [29.4% (5/17)], presence of tortous and dilated capillaries in the papillary dermis [52.9% (9/17) and 76.5% (13/17)] and extravasated erythrocytes [29.4% (5/17)] were found to be more common in palmoplantar psoriasis compared with eczematous dermatitis; but none of them was statistically significant. Interestingly, spongiotic vesicles were seen in most of the patients with psoriasis [76.5% (13/17)]. In conclusion, according to our findings, many features of palmoplantar psoriasis overlapped with those of eczematous dermatitis.

However, detection of multiple parakeratotic foci, placed vertically, alternating with orthohyperkeratosis, could be considered in favor of palmoplantar psoriasis.

Epidemiology
Disease Associations
Pathogenesis
Laboratory/Radiologic/ Other Diagnostic Testing
Gross Appearance and Clinical Variants
Histopathological Features and Variants
Special Stains/ Immunohistochemistry/ Electron Microscopy
Differential Diagnosis
Prognosis
Treatment
Commonly Used Terms
Internet Links

EPIDEMIOLOGY	CHARACTERIZATION
SYNONYMS
INCIDENCE/ PREVALENCE
AGE
SEX
GEOGRAPHY
EPIDEMIOLOGIC ASSOCIATIONS
Long history of psoriasis with provacative agent	Sunlight, UV radiation, alcohol, malignancy, hypocalcemia, NSAIDS, lithium, iodides, beta blockers, penicillin, sulfonamides, progesterone
Preceding psoriasis with atypical features	Onset is usually late in life
Arising without preexisting psoriasis

LABORATORY/ RADIOLOGIC/ OTHER TESTS	CHARACTERIZATION
RADIOLOGIC
LABORATORY MARKERS

GROSS APPEARANCE/ CLINICAL VARIANTS	CHARACTERIZATION
GENERAL
VARIANTS
ACRAL	Arises in acrodermatitis continua Localized to one or more digits with dystrophy of nails
ANNULAR
Annular pustular psoriasis--most common form of pustular psoriasis in children: report of three cases and review of the literature. Liao PB, Rubinson R, Howard R, Sanchez G, Frieden IJ. Duke University School of Medicine, Durham, North Carolina, USA.	Pediatr Dermatol 2002 Jan-Feb;19(1):19-25 Abstract quote Annular pustular psoriasis (APP) is a rare form of pustular psoriasis with a chronic recurrent course and good prognosis. We report three cases of APP in children, two of whom were siblings. Review of the medical literature reveals that a disproportionately high percentage of cases of APP occur in children. In some cases topical therapy can clear the condition, although in severe or recalcitrant disease, systemic therapy may be necessary.
EXANTHEMIC
IMPETIGO HERPETIFORMIS	Flexural surfaces with centripetal spread May be a variant of psoriasis in pregnancy Fetal mortality is high
Recurrent impetigo herpetiformis in a pregnant adolescent: case report. Sahin HG, Sahin HA, Metin A, Zeteroglu S, Ugras S. Department of Obstetrics and Gynecology, University of Yuzuncu Yil, Medical Faculty, Van, Turkey.	Eur J Obstet Gynecol Reprod Biol 2002 Mar 10;101(2):201-3 Abstract quote Impetigo Herpetiformis is a rare pustular dermatosis that typically occurs in pregnant women with unknown etiology. A 17 year old patient who developed Impetigo Herpetiformis for the second time in the 27th week of her 2nd pregnancy is presented. The patient improved with corticosteroids treatment but the lesions did not clear completely and had flare ups during stressful periods which brings us to conclusion that Impetigo Herpetiformis at least has a common pathway with Generalized Pustular Psoriasis in the pathogenesis as stress provoked exacerbations.
LOCALIZED	Pustular psoriasis arising in preexisting plaques of psoriasis
NAILS
Pustular psoriasis of the nails: treatment and long-term follow-up of 46 patients. Piraccini BM, Tosti A, Iorizzo M, Misciali C. Department of Dermatology, University of Bologna, Via Massarenti 1, 40138 Bologna, Italy.	Br J Dermatol 2001 May;144(5):1000-5 Abstract quote BACKGROUND: Pustular psoriasis of the nail apparatus is a common disease that greatly influences the quality of life because of its chronic course and poor response to treatment. OBJECTIVES: To review the clinical and histopathological features, the response to treatment and the long-term follow-up of 46 patients with pustular psoriasis of the nail unit. METHODS: Treatments utilized included oral retinoids (n = 12), oral nimesulide (n = 13), topical calcipotriol (n = 15) and topical steroids (n = 18). Retinoids were utilized as first choice in seven patients with involvement of several digits and in five patients with severe relapses, whereas topical calcipotriol, oral nimesulide or topical steroids were utilized in patients with involvement of a single nail. Topical calcipotriol was also prescribed as maintenance therapy in patients who responded to oral treatment. Twenty-five patients were followed for more than 5 years. RESULTS: Improvement or regression of the lesions was obtained in 23 of 46 patients. Retinoids were effective in six of 12 patients, nimesulide in four of 13, topical calcipotriol in nine of 15 and topical steroids in four of 18. The long-term follow-up showed a complete remission of the disease in only two patients, both affected by pustular psoriasis involving multiple nails. All other patients experienced periodic relapses which were in most cases controlled by regular use of topical calcipotriol. CONCLUSIONS: Severe cases of pustular psoriasis of the nail are best treated with systemic retinoids. Topical calcipotriol is effective in about 50% of patients with localized disorder and is also useful as maintenance therapy after retinoid treatment.
VON ZUMBASCH	Most common variant Explosive onset 30% mortality

HISTOLOGICAL TYPES	CHARACTERIZATION
GENERAL	The histology shows intraepidermal pustules with only mild epidermal hyperplasia, unlike classical psoriasis. There are dilated blood vessels within the superficial dermis associated with lymphocytes

SPECIAL STAINS/ IMMUNOPEROXIDASE/ OTHER	CHARACTERIZATION
SPECIAL STAINS
IMMUNOPEROXIDASE
ELECTRON MICROSCOPY

DIFFERENTIAL DIAGNOSIS	KEY DIFFERENTIATING FEATURES
ECZEMA
Non-pustular palmoplantar psoriasis: is histologic differentiation from eczematous dermatitis possible? Aydin O, Engin B, Oğuz O, İlvan Ş, Demirkesen C.	J Cutan Pathol 2008; 35: 169–173. Abstract quote The differential diagnosis of psoriasis affecting palmoplantar skin might be troublesome because of the anatomic properties of this region. Both palmoplantar psoriasis and eczematous dermatitis of this skin area share similar histologic features. The punch biopsies from 17 patients with psoriasis and 25 with eczematous dermatitis were evaluated, blind to the clinical diagnosis. Vertically situated multiple foci of parakeratosis, alternating with orthokeratosis, were the only statistically significant feature in the differential diagnosis of palmoplantar psoriasis [76.5% (13/17), p = 0.005]. In contrast, multiple foci of parakeratosis [70.6% (12/17)], loss of granular layer at least in focal areas [41.2% (7/17)], presence of neutrophils at the summits of parakeratosis [4% (1/17)], presence of neutrophils and/or plasma in the parakeratotoic foci [94.1% (16/17) and 11.8% (2/17)], psoriasiform epidermal hyperplasia [88.2% (15/17)], spongiosis restricted to the lower parts of the epidermis [47.1% (8/17)], dyskeratotic cells [82.4% (14/17)], thinning of suprapapillary plate [58.8% (10/17)], edema of the papillary dermis [29.4% (5/17)], presence of tortous and dilated capillaries in the papillary dermis [52.9% (9/17) and 76.5% (13/17)] and extravasated erythrocytes [29.4% (5/17)] were found to be more common in palmoplantar psoriasis compared with eczematous dermatitis; but none of them was statistically significant. Interestingly, spongiotic vesicles were seen in most of the patients with psoriasis [76.5% (13/17)]. In conclusion, according to our findings, many features of palmoplantar psoriasis overlapped with those of eczematous dermatitis. However, detection of multiple parakeratotic foci, placed vertically, alternating with orthohyperkeratosis, could be considered in favor of palmoplantar psoriasis.

TREATMENT	CHARACTERIZATION
GENERAL
INFLIXIMAB
Rapid response to infliximab in severe pustular psoriasis, von Zumbusch type. Newland MR, Weinstein A, Kerdel F. Department of Dermatology and Cutaneous Surgery, University of Miami, 1444 NW 9th Avenue, Miami, FL 33136, USA.	Int J Dermatol 2002 Jul;41(7):449-52 Abstract quote Tumor necrosis factor-alpha (TNF-alpha) is a chemokine secreted by T cells which is thought to play a critical role in the pathophysiology of psoriasis. The monoclonal antibody, infliximab, complexes with TNF-alpha, rendering it inactive. A recent clinical trial has reported the clinical benefit and safety of infliximab in moderate to severe plaque psoriasis. We report a case of rapid response and clinical benefit using infliximab in severe pustular psoriasis of von Zumbusch.

Non-pustular palmoplantar psoriasis: is histologic differentiation from eczematous dermatitis possible?

J Cutan Pathol 2008; 35: 169–173. Abstract quote