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PYODERMA GANGRENOSUM (PG) ICD-10: L88
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PG is an idiopathic, either acute or chronic, severely debilitating skin disease.
It is characterized by neutrophilic infiltration, destruction of tissue, and ulceration.
It occurs most commonly in association with a systemic disease, especially arthritis, inflammatory bowel disease, hematologic dyscrasias, and malignancy, but may also occur alone.
Characterized by the presence of painful, irregular, boggy, blue-red ulcers with undermined borders and purulent necrotic bases.
There is no laboratory test that establishes the diagnosis.
The mainstays of treatment are immune-suppressive or -modulating agents.
Relapses occur in most patients and there is significant morbidity.
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Rare, prevalence unknown. All age groups affected with a peak between 40 and 60 years. Slight preponderance of females.
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ETIOLOGY AND PATHOGENESIS
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Unknown. Although called pyoderma, it does not have a microbial etiology. PG is counted among the neutrophilic dermatoses because of the massive neutrophilic infiltrates within the skin. It may belong to the autoinflammatory disease spectrum.
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CLINICAL MANIFESTATION
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Three Types Acute. Acute onset with painful hemorrhagic pustule or painful nodule either de novo or after trauma. There is the phenomenon of pathergy, where a needle prick, insect bite, biopsy, or other minimal trauma can trigger a lesion. Chronic: Slow progression with granulation and hyperkeratosis. Less painful. Bullous: True blisters often hemorrhagic and associated with hematologic disease.
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Skin Lesions Acute. Superficial hemorrhagic pustule surrounded by erythematous halo; very painful (Fig. 7-1). Breakdown occurs with ulcer formation, whereby ulcer borders are dusky-red or purple, irregular and raised, undermined, boggy with perforations that drain pus (Fig. 7-2). The base of the ulcer is purulent with hemorrhagic exudate, partially covered by necrotic eschar (Fig. 7-3), with or without granulation tissue. Pustules both at the advancing border and in the ulcer base; a halo of erythema spreads centrifugally at the advancing edge of the ulcer (Fig. 7-3). Chronic: Lesions may slowly progress, grazing over large areas of the body and exhibiting massive granulation within the ulcer from the outset (Fig. 7-4) with crusting and even hyperkeratosis on the margins (Fig. 7-5). Lesions are usually solitary but may be multiple and form clusters that coalesce. Most common sites: Lower extremities (Figs. 7-2 and 7-5) > buttocks > abdomen (Fig. 7-3) > face (Fig. 7-4). Healing of ulcers results in thin atrophic cribriform scars. Bullous: Blisters from the outset, often hemorrhagic, followed by ulceration.
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