Ulcerative colitis (UC) is a type of Inflammatory Bowel Disorder (IBD), a chronic condition characterized by inflammation of the large intestine and rectum. It doesn’t only affect the gut, however—almost a third of patients with IBD develop skin lesions as a complication of UC. At times, the skin disorder precedes the gastrointestinal symptoms of ulcerative colitis, but they can also occur along with or long after the onset of IBD.
There are at least a dozen skin disorders associated with ulcerative colitis. These are grouped into several types depending on the nature of association with the disease:
Reactive disorders caused by the physical changes associated with IBD: these disorders include erythema nodosum, pyoderma gangrenosum, pyodermatitis-pyostomatitis vegetans, Sweet’s syndrome and cutaneous polyarteritis nodosa.
Manifestations caused by malnutrition or malabsorption: with impaired digestion caused by IBD, patients can develop a zinc, vitamin, or iron deficiency which affects the skin.
Manifestations caused by drug therapy: drugs known to cause skin complications include salicylates, immunosuppressors, biological agents, antibiotics and steroids.
There are also a number of miscellaneous manifestations that may be caused by a combination of factors. Conditions include epidermolysis bullosa acquisita, bullous pemphigoid, squamous cell carcinoma-Bowen’s disease, hidradenitis suppurativa, secondary amyloidosis, and psoriasis.
Because IBD-associated skin conditions vary widely in nature, they should be treated on an individualized basis that is directed at treating both the dermatologic condition and the underlying cause, IBD.
10 Skin Disorders Linked to Ulcerative Colitis
1. Erythema nodosum
With almost 10% of UC patients developing erythema nodosum, this skin condition is the most common one among UC patients.
Symptoms of Erythema nodosum:
Appearance of tender, red nodules or bruise-like markings on a person's arms or legs. With ulcerative colitis, this condition tends to manifest during a flare-up and go away with remission of UC.
2. Pyoderma gangrenosum
Pyoderma gangrenosum is a rare but serious skin disorder that occurs in roughy 2% of patients with IBD. Its pathology is not necessarily related to the activity of IBD, often occurring in patients in clinical remission from IBD.
Symptoms of pyoderma gangrenosum
There are several variations of this condition. Generally, it is characterized by clusters of blisters or small papules on the skin (often on the arms, ankles, or surrounding a stoma). As the condition progresses, the clusters break down to form small ulcers with a distinct “cat’s paw” shape. The lesions can appear as deep ulcers with well-defined borders, usually violet or blue in color.
Researchers believe that psoriasis shares similar immunopathogenic mechanisms to those that cause IBD; this condition is linked to issues with the immune system. There’s also evidence that there’s a genetic link between psoriasis and IBD, but more research is needed to fully understand the relationship between genes, psoriasis, and IBD.
Symptoms of psoriasis
Red, patchy skin with a splotchy appearance, often surrounded or covered by a build-up of dead skin cells.
Hives manifest as part of the body’s reaction to an immune response; this is commonly associated with the body’s immune response to allergens. In UC, hives can manifest as a chronic condition caused by the body’s reaction to UC medication.
Symptoms of hives
Raised red spots forming a rash. Hives can appear on any part of the body.
5. Bowel-associated dermatosis-arthritis syndrome (BADAS)
This rare condition has been linked to the inflammation caused by gut bacteria. The overgrowth of bacteria results in the production of antibodies in the gut, which is thought to cross-react with the skin and joints.
Symptoms of BADAS
First, small bumps appear on the upper chest, legs, and arms. Over 1 or 2 days, these bumps can turn into painful pustules that remain for 1-2 weeks. The appearance of pustules is linked to the activity of IBD and can present alongside symptoms such as fever and abdominal pain.
6. Pyodermatitis-pyostomatitis vegetans
Pyodermatitis-pyostomatitis vegetans is the joint manifestation of two distinct (but related) skin conditions: pyodermatitis vegetans, which affects the armpit or groin, and pyostomatitis vegetans, which affects the mouth. Grouped together, they’re referred to simply as PPV.
Symptoms of PPV
Red pustules that form in the skin folds of the armpit and groin, and pustules or ulcers that form in the mouth. Symptoms of PPV will typically occur after a patient has UC for several years. In fact, sometimes patients are diagnosed with PPV before they are diagnosed with UC.
7. Sweet's syndrome
Sweet's syndrome is linked to UC flare-ups, caused by the presence of antibodies that are produced in the body’s immune response.
Symptoms of Sweet’s syndrome
Skin lesions look like small red or purple bumps on the upper limbs, face, or neck. Over time, these develop into tender lesions. During diagnosis, it can be difficult to distinguish between Sweet’s syndrome and the more common erythema nodosum, which can manifest with similar-looking lesions on the limbs.
Vitiligo is a skin condition in which pigment-producing cells are destroyed. It has been linked to a variety of autoimmune disorders. Some studies have observed that the same TNF-α inhibitors used to treat IBD can also treat vitiligo. However, the relationship is complicated, as research has also revealed cases of patients already being treated with TNF-α inhibitors developing de novo manifestations of vitiligo.
Symptoms of vitiligo
Vitiligo is characterized by the formation of irregular white patches anywhere on the body, but most often on the face, elbows, knees, hands, feet, and genitals.
9. Leukocytoclastic vasculitis
Also called hypersensitivity vasculitis, this condition occurs when capillaries (small blood vessels) under the skin become inflamed. This condition is linked to both the onset of UC and flare-ups, and it typically goes away once a UC patient enters remission. Symptoms of leukocytoclastic vasculitis can precede the onset of UC by a period of up to two years.
Symptoms of leukocytoclastic vasculitis
When the inflamed blood vessels die, they cause the development of purple spots (called purpura) on the skin of the legs or ankles.
10. Skin complications of acrodermatitis enteropathica (zinc deficiency) and anemia (iron deficiency)
Both caused by malabsorption or malnutrition associated with UC, zinc and iron deficiencies can cause skin complications, in addition to other symptoms.
Symptoms of zinc deficiency
Erythematous patches, or itchy red patches that can harden and turn to crusted vesicles, bullae, or pustules. These are typically found on the mouth, anus, limbs, fingers, or scalp.
Symptoms of iron deficiency
Angular cheilitis (inflammation at the corners of the mouth) and pale skin.
New, potentially safer Ulcerative Colitis medications are emerging, including ABT-494 an oral medication by the makers of Humira. This oral medication is free of cost and looking for new patients. Availability is limited, see if you apply here.
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