Metastatic Crohn Disease: A Review of Dermatologic Manifestations and Treatment

Treatment

Because MCD is relatively rare, there are no known randomized trials suggesting a particular medical or surgical treatment. In a review of perineal MCD from 2007, the 40-year-old recommendation by Moutain³ opting for surgical debridement versus medical management still resonates, particularly for perineal disease, as an effective measure in all but the mildest of presentations.⁵¹ However, recent case reports also suggest that the tumor necrosis factor α (TNF-α) inhibitors such as infliximab and adalimumab should be considered prior to surgery even with severe perineal MCD.⁵¹ Moreover, even if medical management with TNF-α inhibitors or some combination of immunosuppressants and antibiotics does not eradicate the disease, it often helps reduce the size of the ulcers prior to surgery.⁵² With a limited understanding of MCD, one might think that removal of the affected bowel would eliminate cutaneous disease, but it has been shown that this strategy is not effective.^53,54

The composition and location of the particular lesion affects the trajectory of treatment. For example, MCD manifesting as local ulcers and plaques has been described as responding well to topical and intralesional steroids.^10,55,56 In the case of penile swelling and/or phimosis, circumcision has been helpful to improve the patient's ability to void as well as to attain and maintain erection.¹⁰ In the case of scrotal swelling secondary to MCD, early treatment (ie, within 4 to 6 months) with oral steroids and/or metronidazole is likely beneficial to prevent refractory edematous organization of the tissue.⁵⁷

As a general rule, an effective treatment will include a combination of an immunosuppressant, antibiotic therapy, and sometimes surgery. The most commonly used immunosuppressant agents include topical or intralesional steroids, infliximab,^43,58 cyclosporine A,^59,60 dapsone, minocycline, thalidomide, methotrexate, mycophenolate mofetil, sulfasalazine, azathioprine, tacrolimus, and 6-mercaptopurine.⁴ Steroids have been the conventional treatment of extraintestinal manifestations of CD⁶¹; however, perineal CD has been poorly controlled with systemic steroids.⁶² If steroids are found not to be effective, sometimes agents such as dapsone or thalidomide are considered. One case report noted stabilization of MCD penile ulcers with oral thalidomide 300 mg once daily, oral minocycline 100 mg once daily, and topical tacrolimus 0.3% with benzocaine twice daily with continuation of prednisolone and methotrexate as parts of previously unsuccessful regimen.⁵²

Metronidazole is perhaps the most commonly used antibiotic, having been a component of many successful regimens.^4,63 For example, a 27-year-old patient with MCD presenting as a nonhealing ulcerative lesion in the subcoronal area of the penis and scrotum was treated successfully with a 6-month course of mesalamine, prednisone, and metronidazole.⁴⁵ Another case report of vulvar MCD reported initial success with intravenous methylprednisolone, ciprofloxacin, and metronidazole.²³ The primary limitation of metronidazole is that subsequent tapering of the dose seems to result in recurrence of disease.⁶⁴ Consequently, patients must remain on the antibiotic for an indeterminate course, with dosages ranging from 5 mg/kg daily in adolescents⁶⁵ to 1000 to 1500 mg daily in adults.⁶⁶

Of the various immunosuppressants available, infliximab has been listed in numerous reports as a successful agent in both the induction and maintenance of extraintestinal manifestations of CD including MCD.^67-71 Infliximab has been reported to be effective in the treatment of penile and scrotal edema secondary to MCD that did not respond to other immunosuppressants including oral prednisolone, azathioprine, and cyclosporine.⁴³ Infliximab may be a good option to help heal draining fistulas, particularly in combination with an antibiotic such as metronidazole and ciprofloxacin, which helps to prevent abscess formation during healing.⁷² The response to infliximab has been dramatic, with resolution of cutaneous lesions after just 6 weeks in some cases.⁷³ The dosing regimen of infliximab has been suggested at 5 mg/kg administered at 0, 2, and 6 weeks, with subsequent maintenance infusions every 10 weeks,⁷⁰ or at 0, 4, and 12 weeks, with subsequent infusions every 8 weeks.⁴³

Adalimumab may be considered as an alternative to infliximab and is potentially less allergenic as a fully humanized monoclonal antibody to TNF-α, which also has been used successfully to both induce and maintain remission of moderate to severe CD.^42,74,75 Proposed dosing of adalimumab includes a loading dose of 160 mg subcutaneously on day 1, followed by an 80-mg dose 2 weeks later and a 40-mg maintenance dose every other week indefinitely.⁴⁸ Of note, adalimumab has been noted in the literature to have many potential side effects, including one particular case in which severe headaches were attributed to its use.⁵⁹ As a consequence of the headaches, the patient was switched from adalimumab to cyclosporine and responded well with no subsequent flare-ups on follow-up.

In summary, treatment of MCD depends on cutaneous location, severity, physician experience with certain antibiotics or immunosuppressants, availability of medication, and patient disposition. It seems reasonable to attempt medical management with one or more medical regimens before committing to surgical intervention. Furthermore, even with debridement, curettage, skin graft, or other surgical strategy, the patient is likely to require some period of immunosuppression to provide long-lasting remission.

Conclusion

Patients with inflammatory bowel disease often develop dermatologic sequelae, with MCD being a rare but serious process. Patients may present with a wide array of physical concerns and symptoms, many resembling other disease processes. As such, education and a high index of suspicion are needed for proper diagnosis and treatment.