Bowel bypass syndrome: skin features may resemble Sweet’s syndrome

Links checked 3/04/17.

What is bowel bypass syndrome?

Bowel bypass syndrome (Cheng, 2012).

Bowel bypass syndrome is also known as bowel-associated dermatitis-arthritis syndrome and blind loop syndrome.

Bowel bypass syndrome is a relapsing condition characterised by rash and arthritis. It is most commonly associated with bowel shortening surgery, where a ‘blind loop’ of bowel is created. This kind of surgery was previously popular for the treatment of morbid obesity. Up to 20% of patients undergoing bowel bypass surgery develop bowel bypass syndrome.

A similar syndrome has been reported in people who have not had bowel bypass surgery (bowel bypass syndrome without bowel bypass). In these cases associated conditions have included:

  • Diverticulitis.
  • Inflammatory bowel disease.
  • Peptic ulcer disease.

What causes bowel bypass syndrome?

Bowel bypass syndrome is thought to be caused by bacterial overgrowth in a blind loop of bowel. A blind loop is a length of small intestine which digested food does not pass through. The effect is shortening of the small intestine, which leads to reduced absorption of fats and subsequent weight loss.

Bacterial overgrowth in the blind loop leads to release of bacterial antigens into the circulation. These antigens are called peptidoglycans. Peptidoglycans bind with circulating antibodies and these antibody-antigen complexes are deposited into skin and joints causing inflammation.

Bacteria identified as having a causative role in bowel bypass syndrome include:

  • Escherichia coli.
  • Bacteroides fragilis.
  • Streptococcus species.

What are the symptoms of bowel bypass syndrome?

Onset of symptoms of bowel bypass syndrome is usually 1-6 years following bowel bypass surgery. Symptoms usually last 2-4 weeks and may recur every 4-6 weeks.

Skin features:

  • Small red bumps (papules), blisters and pustules on trunk and upper arms.
  • May resemble acute neutrophilic dermatosis (Sweet’s syndrome).
  • Erythema nodosum.
  • Panniculitis.

Non-cutaneous features:

  • Fever.
  • Muscle aches and pains.
  • Non-destructive polyarthritis (affecting many joints).
  • Tenosynovitis (inflammation of tendons).

Treatment of bowel bypass syndrome

Surgical excision of the blind loop or revision of the bowel bypass cures bowel bypass syndrome.

Short courses of corticosteroids (steroids)* are effective for symptoms but not curative.

Antibiotics may also be beneficial. Regimes reported to be effective include:

  • Minocycline*.
  • Erythromycin.
  • Clindamycin.
  • Cotrimoxazole
  • Metronidazole.

* Also treatments for Sweet’s syndrome.


Cheng, H. (2012) Bowel bypass syndrome. DermNet NZ (online). Accessed 3/04/17.

Medical information.

Ashok, D. and Kiely, P. (2007) Bowel associated dermatosis – arthritis syndrome: a case report. Journal of Medical Case Reports (online).

Oldfield, C., Heffernan-Stroud, L., Buehler-Bota, T. and Williams, J. (2016) Bowel-associated dermatosis-arthritis syndrome (BADAS) in a pediatric patient. Journal of the American Academy of Dermatology, May; 2(3): 272–274 (online).

Patton, T., Jukic, D. and Juhas, E. (2009) Atypical histopathology in bowel-associated dermatosis-arthritis syndrome: A case-report. Dermatology Online Journal. 

Zhao, H., Zhao, L., Shi, W., Luo, H., Duan, L., You, Y., Li, Yand Zuo, X. (2016) Is it bowel-associated dermatosis-arthritis syndrome induced by small intestinal bacteria overgrowth? SpringerPlus, Sep 13;5(1):1551 (online).

© 2012-2017 Sweet’s Syndrome UK


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