Severe contiguous perianal Crohn's disease.

Introduction

Crohn's disease (CD) is an idiopathic inflammatory bowel disease that is characterized by noncaseating granulomas that occur in the gastrointestinal tract. This disease is chronic, incurable, and prone to relapse. CD is frequently associated with skin and mucous membrane lesions.

The skin is among the most common sites for extraintestinal involvement in CD. Estimated incidence ranges from 22% to 44% and includes distant cutaneous (metastatic) CD, contiguous perianal CD, oral CD, reactive skin findings (including erythema nodosum and pyoderma gangrenosum), and nutritional skin changes. The site of involvement can influence lesion morphology. Contiguous cutaneous CD distinguishes from metastatic CD, as it extends directly from the gastrointestinal tract. Lesions that appear on the legs often present as intact inflammatory papules and plaques, whereas those involving intertriginous and genital skin usually ulcerate owing to the propensity for maceration in these sites. We describe a severe and extensive case of CD with perianal involvement contiguous to an anal CD lesion.

Case report

A 57-year-old man was admitted with an unhealed perineal wound. There was a history of perineal abscess incised and drained in 2012. After 1 year, an ischiorectal abscess and associated fistula developed. The patient underwent a surgical procedure and remained asymptomatic until 2014. Gross ulceration of the perianal region and perineum then developed extending forward to involve the scrotum and bilateral groin area (Fig 1). Colonoscopy found a contiguous lesion at the anal area. Biopsy found sarcoid foci typical of Crohn's disease (Fig 2). No acid alcohol-fast bacilli were found. He was treated with metronidazole (1-2 g/d), prednisone (70 mg/d) and mesalazine (4 g/d plus 750 mg in rectal mesalazine suppositories). The patient started to show improvement but suffered from dilated cardiomyopathy; severe heart failure developed and he died after 1 month.

Fig 1

Severe CD. Gross ulceration of the perianal region and perineum extending forward to involve the scrotum and bilateral groin area.

Fig 2

Noncaseating granulomatous inflammation with multinucleate giant cells and lymphoplasmocytic infiltration in the reticular dermis. (Hematoxylin-eosin stain; original magnification: ×100.)

Discussion

CD is a chronic, relapsing, multisystemic inflammatory disease of unknown etiology, characterized by noncaseating granulomas. The differential diagnosis of perianal CD is broad largely because of its nonspecific and variable presentation. Diagnostic considerations often reflect the site of involvement. Clinically, lesions of CD involving intertriginous skin may resemble metastatic CD, hidradenitis suppurativa, acquired zinc deficiency acrodermatitis enteropathica, periorificial tuberculosis, or even an intertrigo. CD resembles sarcoidosis by histopathologic examination and characteristically presents with noncaseating granulomatous inflammation involving the papillary and reticular dermis with occasional extension into the subcutaneous fat.

In our patient, granulomas were composed of epithelioid and multinucleated histiocytes with a conspicuous lymphocytic infiltrate. Plasma cells and eosinophils were also present, whereas neutrophils and foci of necrobiosis were absent. The inflammatory infiltrate surrounded dermal blood vessels, a phenomenon described as granulomatous perivasculitis (Fig 3). The contiguous lesion observed at the anal area confirmed that our patient presented with contiguous perianal CD instead of metastatic CD. Severe perianal disease, bleeding, or severe pain are found to be indications for surgery in 3% of cases, whereas in fistulizing disease, these symptoms are indications for surgery in 8% of cases. Oral metronidazole has notable efficacy for treating CD when glucocorticosteroids fail.

Fig 3

The inflammatory infiltrate surrounded dermal blood vessels, a phenomenon described as granulomatous perivasculitis. (Hematoxylin-eosin stain; original magnification: ×200.)