Dermatological Manifestations of Inflammatory Bowel Disease: An Overview

Introduction:

Inflammatory bowel disease (IBD) is a long-term disease marked by inflammation of the gastrointestinal tract. It primarily affects the intestines, but inflammatory bowel disease can also occur in other body parts, including the skin. Up to 40 percent of people with IBD experience some form of skin involvement. These dermatological manifestations can vary widely in appearance and severity. Some are directly related to the underlying inflammation of IBD, while others are secondary complications. This article briefly explains dermatological manifestations associated with inflammatory bowel disease.

What Is Inflammatory Bowel Disease?

Inflammatory bowel disease (IBD) is a long-term inflammatory disease of the intestinal tract. The two major types of IBD are ulcerative colitis (UC) and Crohn’s disease (CD). As the name indicates, ulcerative colitis is limited to the colon and rectum (normally continuous lesions in the rectum and colon) and affects only the gut's inner lining. In contrast, Crohn’s disease can affect any portion of the gut from mouth to anus as it is not continuous and affect the whole thickness of the bowel wall.

What Are the Dermatological Manifestations of Inflammatory Bowel Disease?

1. Dermatological Manifestations Related to Inflammatory Bowel Disease:

• Aphthous Stomatitis (canker sore): Aphthous stomatitis occurs in about 10 percent of patients with inflammatory bowel disease. Aphthous stomatitis, also known as canker sores, are painful ulcers that usually appear inside the mouth.

• Erythema Nodosum: Erythema nodosum (EN) is the most common manifestation of inflammatory bowel diseases, affecting about 3 to 10 percent of ulcerative colitis patients and 4 to 15 percent of individuals with Crohn's disease. It occurs more commonly in women. Erythema nodosum is an inflammatory skin disease characterized by painful red bumps(nodules) that are usually present on the lower legs, ranging from 1 to 5 cm in diameter, and can sometimes affect other areas also, such as the face, trunk, and upper extremities. The lesions are thought to result from inflammation of the subcutaneous fat tissue and are considered a reactive response to systemic inflammation.

• Psoriasis: Psoriasis is an inflammatory skin disease that causes red, scaly patches on the skin. These patches can appear anywhere on the body but are most commonly observed on the elbow., knees, joints, and scalp. Psoriasis has been observed to have a higher prevalence in individuals with IBD compared to the general population. About 7 to 11 percent of patients with IBD develop psoriasis. It is more common in Crohn's disease than ulcerative colitis.

• Epidermolysis Bullosa: Acquisita About 30 percent of epidermolysis bullosa acquisita (EBA) patients are affected by IBD, most commonly Crohn's disease.EBA is an autoimmune disorder induced by autoantibodies against type VII collagen. It is characterized by skin fragility, blister formation, and scarring, mainly localized at the areas that are easily injured, such as hands, knees, and feet.

• Pyoderma Gangrenosum: Pyoderma gangrenosum (PG) is a rare painful skin disease occurring in about 1 to 2 percent of patients with inflammatory bowel disease. It can occur before, during, or after the IBD onset and can display a course independent from IBD. Pyoderma gangrenosum is prevalent in women and more commonly occurs in individuals with a family history of ulcerative colitis. The defining features of PG are large, painful skin ulcers that typically occur on the skin.

• Sweet’s Syndrome: Sweet’s syndrome is an acute neutrophilic dermatosis. The association of Sweet's syndrome with inflammatory bowel disease is not common. It occurs more frequently in women than in men, mostly between the 3rd and 5th decade of life. Moreover, it is more prevalent in Crohn’s disease than in ulcerative colitis. Sweet’s syndrome is marked by the sudden onset of fever and painful rashes, mainly involving the face, neck, and upper limbs.

2. Dermatological Manifestations Secondary to Inflammatory Bowel Disease Treatment:

Dermatological disorders can be caused by several medications used to treat IBDs. In particular, in the last few years, anti-TNF-α agents used in IBDs have been increasingly reported to cause dermatological side effects. Skin lesions generated by TNF-α antagonists include adverse skin reactions, infectious complications, and skin cancer.

• Adverse Reactions: skin allergic reactions may occur due to the drugs used in the treatment of IBD, especially TNF-α antagonists. Anti-TNF-α agents can induce skin adverse reactions, either localized or generalized. Injection site reactions like readiness, swelling, itching, and pain can occur following the administration of adalimumab, etanercept, and certolizumab pegol.

• Infectious Complications: Although anti-TNF-α agents provide significant benefits to many patients with chronic inflammatory bowel disease, These medicines may also suppress the immune system, increasing the risk of certain infections. Individuals taking TNF antagonist drugs are at an increased risk of getting bacterial, viral, and fungal infections. Skin infections induced by bacteria such as erysipelas, cellulitis, and abscesses have been reported in about 0.1 to 7 percent of patients. About 3 percent of individuals treated with TNF antagonists experience reactivation of the herpes virus, particularly the varicella-zoster virus.

• Skin Cancers: There is ongoing controversy over the higher frequency of skin malignancies in individuals treated with anti-TNF-α medications. A higher risk for skin malignancies other than melanoma, especially basal cell carcinomas, has been identified by certain researchers. Patients treated with a combination of thiopurines and TNF-α inhibitors have been reported to have a higher incidence of cutaneous lymphomas, such as mycosis fungoides and Sézary syndrome.

3. Dermatological Manifestations Due to Nutritional Malabsorption:

In IBD patients, skin lesions can also be caused by nutritional deficiencies, which include:

• Stomatitis glossitis, angular cheilitis due to vitamin B deficiency.

• Pellagra due to niacin deficiency.

• Acrodermatitis enteropathica occurs due to the deficiency of zinc.

• Scurvy (vitamin C).

• Purpura (vitamin C and K).

• Xeroderma, or dry skin and unspecified eczema (essential fatty acid deficiency).

• Hair and nail abnormalities occur due to the malabsorption of amino acids and protein.

Conclusion:

In conclusion, dermatological manifestations in individuals with inflammatory bowel disease are diverse, ranging from those directly linked to the inflammatory nature of the disease to complications arising from its treatment and nutritional deficiencies. A comprehensive understanding of these manifestations is crucial for clinicians managing IBD patients, facilitating timely diagnosis and appropriate intervention for improved overall care.