What is anogenital granulomatosis?
Anogenital granulomatosis (AGG) is a rare chronic inflammatory granulomatous disease of unknown aetiology. It is characterised by histological evidence of non-caseating granulomatous inflammation and can present with diffuse penile, scrotal, vulvar, or anoperineal swelling.
Who gets anogenital granulomatosis?
AGG is an uncommon condition that has been reported in both females and males of varying age groups from 1–79 years of age with the majority between 20–35 years of age. In 38% of cases, AGG can be associated with an underlying systemic condition such as Crohn disease or sarcoidosis. Associated Crohn disease may be symptomatically silent, or there may be a lag of several years between the appearance of genital swelling or lesions, and objective evidence of associated inflammatory bowel disease.
What causes anogenital granulomatosis?
The cause of anogenital granulomatosis is unknown. It is characterised by granulomatous genital or anoperineal inflammation and lymphoedema. Intralymphatic granulomas have been noted to cause partial or complete occlusion of the drainage of lymphatics, subsequently causing lymphoedema.
What are the clinical features of anogenital granulomatosis?
Most commonly presents as:
- Chronic penile, scrotal, vulval, or anoperineal swelling
- With or without erythema.
Other clinical features include:
- Fissures, perianal tags and ulcers
- Difficulties with urinary flow and sexual intercourse.
What are the complications of anogenital granulomatosis?
- Recurrent cellulitis.
- Impact on mental health and quality of life.
- Urinary flow and sexual difficulties.
How is anogenital granulomatosis diagnosed?
Anogenital granulomatosis is usually diagnosed clinically.
A biopsy is helpful to confirm the diagnosis. The characteristic features seen in biopsy include:
- Scattered, non-caseating epithelioid cell granulomas
- Lymphoedema and granulomas containing epithelioid cells, multinucleated giant cells, and lymphocytes.
Further investigations, such as serum angiotensin-converting enzyme (ACE) and chest radiograph to exclude sarcoidosis can be conducted. Colonoscopy and faecal calprotectin to exclude Chron disease should be considered for patients with gastrointestinal symptoms.
There are reported cases of Crohn disease developing years after symptoms started, therefore long-term follow-up is warranted.
What is the differential diagnosis for anogenital granulomatosis?
- Crohn disease
- Hidradenitis suppurativa
- Lymphoproliferative diseases
- Foreign body granuloma
- Lymphogranuloma venereum
- Granuloma inguinale
- Deep mycoses
What is the treatment for anogenital granulomatosis?
Treatment is challenging and based on limited case studies.
- Compression shorts for support and to reduce discomfort
- Topical steroids
- Tetracyclines, such as doxycycline or minocycline
- Systemic corticosteroids; relapses can occur upon cessation
- Intralesional steroid injection
- Immunomodulators such as azathioprine, mycophenolate mofetil, and methotrexate
- Biological treatment such as tumour necrosis factor-α (TNF-α) inhibitors including infliximab and adalimumab, as some reports show symptom improvement
- Surgical treatment can be considered if refractory cases affect micturition, sexual intercourse, and discomfort.