Blood in the stool + abnormal skin ulcers, can you accurately diagnose it?

Case data: A 31-year-old female patient with a history of systemic lupus erythematosus, perianal condyloma acuminatum, and chronic iron deficiency anemia, intermittent hematochezia, multiple pains of the anogenital organs, and skin ulcers under the left breast for 2 months, and palpitations for 2 days
.

The patient reported to have chronic perianal foul-smelling discharge, but denied any fever, nausea, vomiting, abdominal or perianal pain, melena, or changes in bowel habits
.

The patient underwent upper gastrointestinal endoscopy and colonoscopy 3 years ago.
The results showed that the esophagus, stomach, and duodenum were normal, but there were multiple small rectal and sigmoid colon polyps, as well as internal and external hemorrhoids
.

Duodenal biopsy showed a slight increase in intraepithelial lymphocytes, but the villi structure was preserved
.

Colonic polyp biopsy revealed chronic active colitis with minimal structural deformation and superficial ulcers
.

Immunostaining for cytomegalovirus was negative
.

No targeted treatment was given at that time
.

The patient's past medical history also included antiphospholipid antibody syndrome and IgA nephropathy
.

Treatment drugs include aspirin 81 mg and hydroxychloroquine 200 mg twice a day
.

The patient has sinus tachycardia, but his blood pressure is normal
.

Skin examination revealed exudative ulcers of the skin under the left breast with erythema and hypertrophy (Figure A), and bilateral ulcerative flesh-colored linear plaques with erythematous verrucous papules (Figures B and C)
.

Similar lesions were also observed on the patient's vulva and labia majora
.

Perianal examination revealed multiple ulcerative fleshy lesions with foul-smelling yellow discharge (Figure D)
.

Digital rectal examination showed large skin tags and external hemorrhoids with distal rectal stenosis
.

Laboratory examination results showed that c-reactive protein was 58.
7 mg/dL, hemoglobin was 6.
8 g/dL, and the patient received a blood transfusion
.

Intravenous contrast medium pelvic magnetic resonance imaging revealed 3 perianal fistulas and proctitis with cellular changes
.

Colonoscopy revealed erythema, edema, and fragility of the rectal mucosa, an opening related to the fistula opening, and severe rectal stenosis
.

Anorectal biopsy revealed squamous mucosal ulcers with mixed acute and chronic inflammation
.

Subsequently, a biopsy of the skin ulcer under the left breast of the patient was performed, see Figure EG
.

What should be diagnosed? Analysis and diagnosis of the left submammary skin biopsy revealed granulomatous dermatitis with focal ulcer, pseudoepithelioma-like hyperplasia, dense hyperkeratosis, thickening of the granular layer and spongy formation (Figure E), mixed dermal inflammatory infiltration (Figure F) ), including neutrophils, plasma cells, lymphocytes, tissue cells with scattered multinucleated giant cells (Figure G)
.

Both fungal and acid-fast stains were negative
.

Based on the patient's overall clinical manifestations, multiple physicians have jointly reminded to pay close attention to metastatic Crohn's disease (MCD) and new-onset fistula and stenotic Crohn's colitis with perianal disease
.

Diagnosis result: MCD
.

Knowledge class: MCDMCD is a rare extraintestinal manifestation of Crohn's disease, which can occur at any point in the course of the disease, and its relationship with the severity of the underlying Crohn's disease is unclear
.

MCD often presents as an erythema rubbing ulcer or a well-defined plaque or papule, usually involving the face, trunk, vulva, penis, or legs
.

Typical histological features of MCD include inflammatory infiltrates composed of non-caseating epithelioid granulomas, Langhans giant cells, and epithelioid histiocytes
.

Although granulomatous dermatitis is a unique feature of MCD, it is also related to other diseases, such as mycobacterial infection and primary or drug-induced sarcoidosis
.

MCD lesions are usually chronic and, if left untreated, can lead to significant physical and psychosocial diseases
.

At present, a variety of drugs have been used to treat MCD, with different success rates, but no reliable and effective treatment has been found
.

These drugs include topical or systemic glucocorticoids, metronidazole, immunomodulators (such as methotrexate or azathioprine), and biological agents
.

For refractory cases, surgical resection and debridement may be required
.

Reference: Kuang AG, Bahdi F, Shukla R.
Unusual Skin Ulcerations in a Patient with Hematochezia.
Gastroenterology (2022).
doi: https://doi.
org/10.
1053/j.
gastro.
2021.
12.
267.