Pyoderma gangrenosum


Cutaneous disease with necrotizing and ulceration which is probably a noninfectious manifestation of a Schwartzman-like reaction to an unknown antigen.

An inflammatory neutrophilic dermatosis that presents with the sterile, neutrophilic infiltrate on histopathology.

PG is a rare neutrophilic dermatosis characterized by painful erythematous, or inflammatory papules that frequently progressed to ulcers with a violaceous border.

Estimated incidence is 3-10,000,000 per year.

Overall incidence of 0.63 per hundred thousand person-years.

Female to male ratio of 1.8:1 across all ages.

Rare neutrophilic skin disorder with painful and necrotic ulceration.

Suspected to be mediated by neutrophil dysregulation or an auto inflammatory disease process.

Despite its name, it is neither an infectious or gangrenous process.

Characterized by ulcerations that occur spontaneously or are associated with other systemic disorders, including inflammatory, bowel disease, inflammatory arthropathies, hematological malignancies, and solid tumors.

It frequently occurs in young/middle-aged adults with the median age of 51.6 years.

It is more common in women.

Typical presentation is in inflammatory papule or pustule that progresses to a painful ulceration.

Early lesions of ulcerative pyoderma gangrenosum appear as tender erythematous nodules wor papulopustules that erode to create ulcers with a purulent base and inflammatory, violaceous, and overhanging borders.

Suspected to be related to up regulation of neutrophilic function and secondary release of cytokines such as interleukin-8 which drives the process.

Associated with systemic disease in 50-78% of cases: inflammatory bowel disease, rheumatoid arthritis, or hematologic malignancy.

No specific laboratory or histopathologic findings confirm the diagnosis.

It is associated with pathergy, a condition in which trauma to the skin results in skin lesions or ulcers that may be resistant to healing.

Usually presents as a rapidly advancing painful ulcer, most often on the legs.

It usually has a an irregular violaceous or gunmetal gray undetermind border.

Variants include ulcerative, bulbous, pustular, vegetative, and peristomal forms.

Atypically may appear on the hands, arms, or face with deep erosions was superficial ulcerations with the violaceous or bluegray,bulbous or granulomatous appearing border.

Suspected in patients who develop recurrent ulcerations, with raised, overhanging, purple wound edges, that may be precipitated by surgery and surgical debridement.

Common pathway of neutrophil infiltration and tissue destruction.

Represents an inflammatory dermatosis and is a type of neutrophilic dermatosis.

Has four clinical variants based on morphological features-bullous, pustular, vegetative, and peristomal.

Most common in the third, fourth and fifth decades of life with slightly higher incidence in women.

Misdiagnosed in up to 10% of cases.

Initial presentation similar to a pyogenic infection and incision and drainage may be necessary to make the diagnosis.

Operations may exacerbate the lesion.

Most commonly occurs on the lower extremities, affecting people primarily between the ages of 30 and 60.

More than 50% of patients have associated underlying systemic diseases such as inflammatory bowel disease, a hematologic process, or various forms of inflammatory arthritis.

Highest disease associations are inflammatory bowel disease, rheumatoid arthritis, and myeloid disorders.

Up to 70% of cases associated with systemic illnesses which include: ulcerative colitis, Crohn’s disease, monoclonal gammopathy, seronegative arthritis with inflammatory bowel disease, small joint polyarthritis, rheumatoid arthritis, ankylosing spondylitis, acute myelomonocytic leukemia, hairy cell leukemia, multiple myeloma, chronic active hepatitis, primary biliary cirrhosis, Behcet’s disease, Wegener’s granulomatosis, HIV infection, and adenocarcinoma of the colon.

Course of skin ulcers does not necessarily correlate with underlying disease process.

Lesions may occur in sites of trauma such as those injured by surgery, burns and even venous puncture.

Manifest as a nodule or pustule that expands into a deep ulceration.

The edge of the ulcer is usually well defined and has a blue or violaceous color.

The lesion may have necrosis and exudate and is usually surrounded by an erythematous halo.

Lesions are usually painful and most commonly arise on the lower legs, but can be anywhere including the mucous membranes.

Lesions can by multiple in nature.

Differential diagnosis includes cellulitis, mycoses, cutaneous tuberculosis, superficial gangrene, gummatous syphilis, leishmaniasis, cutaneous Amebiasis, venous stasis disease, drug induced disease, brown recluse spider bite, excessive bromide or iodide ingestion, vasculitis, Sweet syndrome and malignancies.

Diagnosis largely depends on clinical history, histological findings, and exclusion of other inflammatory or ulcerative cutaneous seizes.

Ulcerative most common lesions and occurs primarily on the extremities and lower trunk.

Ulcerative lesions involve the lower extremities 70% of the time and is the type associated with inflammatory bowel disease.

There are four distinctive clinical and histologic variants: ulcerative, pustular, bullous and vegetative.

Pustular lesions on the extensor surface of the extremities indicative of pustular Pyoderma gangrenosum.

Pustular lesions slow to heal and may involve the mucous membranes, axilla and genital areas.

Pustular lesions characterized by subcorneal pustules with papillary dermal edema, neutrophilic infiltration.

Pustular lesions may also be present in inflammatory bowel disease.

Bullous type disease is a superficial blistering dermatosis which is among the least aggressive variants, resembling bullous impetigo.

Bullous type of disease may be associated with leukemia and other hematologic neoplasms.

Vegetative variant is a superficial form that remains confined to the skin, and is usually seen on the trunk and occurs in otherwise health individuals, although may be seen in lymphoproliferative and myelodysplastic disorders.

Vegetative lesions are characterized by pseudo-epitheliallmatous hyperplasia, dermal app abscesses, palisading granulomatous reactions and are typically not associated with systemic illness.

Ulcerated lesions are often associated with systemic diseases including arthritis, inflammatory bowel disease, and monoclonal gammopathies.

Diagnosis based on appearance of the skin lesions and is not associated with a pathognomonic histopathology.

Laboratory testing should include complete blood count, serum protein electrophoresis, erythrocyte sedimentation rate, rheumatoid factor, antinuclear antibody testing, antineutrophil cytoplasmic antibody testing, evaluation of the gastrointestinal tract, culture of the skin lesion and skin biopsy.

Biopsy is non specific but lymphocytic infiltration and fibrinoid necrosis of blood vessel walls frequently seen in peripheral biopsy sites, while neutrophilic infiltration and dermal necrosis is seen in central bilateral biopsy sites.

There are four morphologic subtypes: ulcerative, bullous, pustular, and vegetative.

Its pathogenesis depends on immune dysregulation and genetic factors.

Gene expression of pro-inflammatory cytokines, including tumor necrosis, factor alpha, and Interleukins 1, 8, 12, 15, 17, 23, and 36 are increased in cutaneous lesions.

Several cases of familial PG suggest genetic factors play a role.

Treatment attempts to stop progression of ulcers, promote re-epithelialization and provide pain management.

Management depends on the severity of the disease in the extent of the lesions and

underlying disease.

Local wound care with moist dressings and avoidance of aggressive debridement are generally recommended approaches.

For mild localized lesions topical corticosteroids or tacrolimus are utilized.

Lesions may take several months to heal.

In early lesions topical or intralesional corticosteroids, topical 5-aminosalicylic acid, benzoyl peroxide, intralesional cyclosporine and topical cromolyn may be useful.

Systemic steroids considered mainstay of management.

Responds to corticosteroids and other immunosuppressive agents.

Cyclosporine with or without systemic steroids may be used as an alternative first line treatment.

Postoperative pyoderma gangrenosum is a difficult diagnosis due to the lack of a recognizable disorder mimicking both wound infections and necrotizing fasciitis.

Postoperative pyoderma gangrenosum is also known as postsurgical or pathergic pyoderma granulosum.

Postoperative pyoderma granulosum typically has no underline associated medical disorder.

There are four types: ulcerative, bulbous, pustular, and vegetative.

Atypical and bullous types of pyoderma gangrenosum often linked to hematologic disorders and maybe a presenting sign of leukemia.

Pro inflammatory cytokines, including IL1, IL –8, IL – 12, IL – 15, IL 17, IL – 23, and I L – 36 are recognized receptors at increased levels in cutaneous lesions of pyoderma gangrenosum leading to activation of inflammasone and dysregulation of innate adaptive immunity.


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