Pyoderma Vegetans 

Updated: Mar 26, 2021
Author: Robert A Schwartz, MD, MPH; Chief Editor: Dirk M Elston, MD 



Pyoderma vegetans (PV) is a rare disorder clinically characterized by large verrucous plaques with elevated borders and multiple pustules. Pyoderma vegetans is an eruption of multiple pustular ulcerations; it may have a bacterial etiology similar to chancriform pyoderma.[1, 2, 3, 4]

Hallopeau first characterized this process in 1898.[5] Although its etiology is unknown, this disease has been attributed to bacterial infection in an individual who is immunocompromised[1] ; more recent reports support this theory.[2, 6, 7] Pyoderma vegetans has been associated with ulcerative colitis,[8, 9, 10, 11] diffuse T-cell lymphoma,[6, 12]  alcoholism with malnutrition,[1] HIV infection,[13] chronic myeloid leukemia (CML),[14] and lupus nephritis.[15]

Su et al reported 7 patients with clinically characteristic pyoderma vegetans.[2] These patients had various conditions that compromised their immune systems; these conditions included pulmonary granuloma, chronic granulocytic leukemia, arthritis treated with azathioprine and prednisone, and seminoma treated with x-ray irradiation, which predisposed them to bacterial infections.[2] After pyoderma vegetans was diagnosed, 1 patient developed squamous cell carcinoma and colonic carcinoma. Ishibashi described a patient with pyoderma vegetans without any history of an immunocompromising condition.[16]


The etiology of pyoderma vegetans (PV) is not known, although it is often associated with staphylococcal and streptococcal infections in a patient with an immunosuppressive state or a dysfunction of the immune system. The immunological dysfunction is believed to induce the development of vegetations. In addition to bacterial infections, fungal infections have also been implicated in the context of immunosuppression, as demonstrated by a case of treatment-resistant Trichophyton mentagrophytes –induced tinea manuum resulting in a chronic pyoderma vegetans in a patient with decreased immunoglobulins and impaired phagocytosis.[17]

Diffuse T-cell lymphoma,[6] ulcerative colitis,[8] and HIV infection[13] have been associated with this condition. A patient was described with pyodermatitis-pyostomatitis vegetans associated with ulcerative colitis who, upon immunofluorescence examination, demonstrated in vivo bound and circulating immunoglobulin G antibasement membrane zone antibodies.[18] These antibodies reacted with the bullous pemphigoid antigen 230. The presence of circulating autoantibodies to the bullous pemphigoid antigen 230 in this patient was considered an epiphenomenon, resulting from epidermal damage induced by inflammation of the pyodermatitis-pyostomatitis vegetans. Pyoderma vegetans may also be associated with myelodysplastic syndromes.[19]


The etiology of pyoderma vegetans is not known.


Pyoderma vegetans is rare.


With therapy, the prognosis is good, although this may prove untrue in the face of associated medical conditions, such as HIV, diffuse T-cell lymphoma, and CML, which must be properly addressed.

In patients in whom inflammatory bowel disease does not coexist, pyoderma vegetans has a good prognosis with therapy. In contrast, pemphigus vegetans has a poor prognosis without the continuous use of immunosuppressive drugs.




Some patients with pyoderma vegetans (PV) may have a history of hidradenitis suppurativa.[20, 21] This rare inflammatory dermatosis may involve skin and mucosa with pustular and vesicular plaques. In some patients, vegetating plaques may appear in the axillary, vulvar, and inguinal areas.[22] Disfiguring facial pyoderma vegetans has been described.[23]

Physical Examination

Both clinical and histologic findings are necessary to make the diagnosis of pyoderma vegetans. The plaques are often multiple; some may appear purulent, others hyperkeratotic.[24] At clinical examination, multiple pustules and large verrucous plaques with an elevated border are identified (note the images below). It may rarely appear on the penis.[25] At histologic examination, pseudoepitheliomatous hyperplasia is demonstrated.

A 24-year-old woman with rapidly evolving pyoderma A 24-year-old woman with rapidly evolving pyoderma vegetans.
Pyoderma vegetans. Pyoderma vegetans.


Diagnostic Considerations

Pyoderma vegetans may resemble and needs to be distinguished from cicatricial pemphigoid vegetans[26] and from localized pemphigus vegetans, which may be seen lacking mucosal lesions.[27] The large verrucous plaques of pyoderma vegetans may also suggest verrucous carcinoma.[28]

Pyoderma vegetans mimics deep fungal infections at clinical examination. As a result of this clinical resemblance, pyoderma vegetans has been labeled both mycosislike pyoderma and blastomycosislike pyoderma. North American blastomycosis and pemphigus vegetans, a rare variant of the autoimmune disorder pemphigus vulgaris, also clinically resemble pyoderma vegetans. Rarely, other deep fungal infections, including phycomycosis and coccidioidomycosis, mimic the presentation of pyoderma vegetans.

Botryomycosis, a rare bacterial infection, may present similarly to a fungal infection and may appear similar to pyoderma vegetans. Cutaneous botryomycosis is differentiated by the presence of basophilic granules that resemble the sulfur granules of actinomyces at histologic examination.[29] Depressed immunity is also common to cutaneous botryomycosis, as seen in acquired immunodeficiency syndrome (AIDS).[30, 31] In 1995, Marschalko et al suggested that cutaneous botryomycosis is a subtype of pyoderma vegetans, and they proposed that pyoderma vegetans and cutaneous botryomycosis should be classified together.[32]

Bromoderma, mycobacterial infections, and giant keratoacanthomas are also included in the differential diagnosis.

On the penis, it must be distinguished from penile cancer.[25]

Pyodermatitis-pyostomatitis vegetans, a rare mucocutaneous inflammatory disorder evident as vesicular, pustular, exudative, and vegetating plaques and frequently associated with ulcerative colitis, may require distinction.[33, 34, 35] The inflammatory bowel disease may be asymptomatic.[36]  Pyodermatitis pyostomatitis vegetans may be viewed as an oral variant of pyoderma vegetans.

It should be distinguished also from pyoderma gangrenosum.[37]

Necrobiosis lipoidica with seeming progression to pyoderma vegetans was described, perhaps a coincidental association.[38]

Differential Diagnoses



Laboratory Studies

Pathogenic organisms, such as Staphylococcus aureus, are grown from wound cultures, and cultures should also be taken for fungi and mycobacteria.

Direct and indirect immunofluorescence can aid in differentiating pyoderma vegetans (PV) and pemphigus vegetans.[20, 39]

Hidradenitis suppurativa may cause an immune complex deposition in the skin, which precipitates the PV reaction. This reaction can be seen as a nonspecific immunoreactant deposition with direct immunofluorescence.[20]

Histologic Findings

Two predominant features are found in pyoderma vegetans: pseudocarcinomatous hyperplasia and numerous abscesses in both the hyperplastic epidermis and the dermis. The abscesses can be made up of neutrophils or eosinophils.



Medical Care

No standardized treatment plan is available for pyoderma vegetans (PV), although antibiotic treatment has often been used with variable results.[40] Other options include curettage and topical therapies, including aluminium subacetate soaks plus attention to any underlying systemic illness.[41]

Topical wound care with copper sulfate or aluminum subacetate dressings and intravenous antibiotics successfully treated 5 of 7 patients with pyoderma vegetans.[2]

Topical aluminum acetate soaks with intravenous ceftriaxone had moderate success at clearing pyoderma vegetans in another patient.[20]

Over a course of 2 months, the application of zinc oxide along with the intralesional injection of corticosteroids completely cleared lesions on the perianal area of 1 patient.[39]

A vegetating lesion on the dorsum of a patient's hand was completely cleared with 4 weeks of 2 g of ampicillin daily and x-ray irradiation.[32]

In the treatment of 1 patient whose lesions were refractory to antibiotic treatment, topical application of disodium chromoglycate, which is used for the management of chronic leg ulcers[42] and pyoderma gangrenosum,[43] induced the healing of lesions.[7, 44]

Ichimiya et al reported successful treatment with etretinate and systemic steroids.[45]

A patient with pyoderma vegetans attributed to Candida albicans was treated successfully with itraconazole.[46]

Other options include low-dose sulfasalazine[47] or infusions of 20% human albumin (100 mL) for 5 days, followed by methylprednisolone (40 mg/d) for a month.[48]

Surgical Care

Antibiotic treatment has been successfully supplemented with laser debridement or curettage to clear lesions.[49] Surgery is a therapeutic option when conservative treatment proves ineffective. Complete excision and skin grafting may be performed with a good postoperative result.[50]



Medication Summary

The goals of pharmacotherapy are to reduce morbidity and to prevent complications. Reportedly, pyodermatitis-pyostomatitis vegetans associated with ulcerative colitis has been successfully treated in one patient with total colectomy and topical tacrolimus.[51]

Topical skin products

Class Summary

Applied locally, these products may dry affected area by reducing the secretory function of the skin glands. They may also toughen the skin to help prevent reinfections, and they may have antiseptic properties.

Aluminum acetate solution (Burow solution)

Dissolve aluminum acetate tablets in water to get a 1:10 to 1:40 solution. Aluminum acetate solution has a drying effect on vesicular or wet dermatoses.

Zinc oxide topical (Aveeno Baby Organic Harvest Diaper Rash Cream, Desitin, Desitin Creamy)

Zinc oxide provides relief of minor skin irritations.


Class Summary

Therapy must cover all likely pathogens in the context of this clinical setting.

Ampicillin (Marcillin, Omnipen, Polycillin, Principen, Totacillin)

Ampicillin has bactericidal activity against susceptible organisms. It is an alternative to amoxicillin when the patient is unable to take medications orally.