Fat lip in adolescent boy with Crohn's disease

Diagnosis: Oral Crohn's disease

Oral CD may present with labial enlargement, oral ulcers, mucosal swelling, fissuring of the tongue, facial nerve palsy, facial swelling and erythema, mucosal tags, gingival enlargement, and cervical lymphadenopathy.² Oral aphthous ulcers and pyostomatitis vegetans also may develop. These lesions may result in fibrosis and adhesion formation.

PATHOPHYSIOLOGY

Theories explaining the exact cause of CD include a persistent and specific infection, dysbiosis, defective mucosal barrier function, defective microbial clearance, and aberrant immunoregulation.⁴ Both the innate and acquired immune responses are activated, and tolerance to commensal bacteria is lost, with tumor necrosis factor (TNF) and interleukin (IL)-12 p40 being implicated in the pathogenesis. In CD, IL-12 is increased in the mucosa of the gastrointestinal tract, which triggers the TH1 response and increases interferon (IFN)-γ. This leads to an unregulated cycle of inflammation and additional activation of matrix metalloproteinases from INF-γ and TNF-α.⁵ As a result, chemotactic agents attract large numbers of neutrophils and histiocytes to the inflamed mucosa, leading to the formation of noncaseating granulomas.

DIAGNOSIS

A child or adolescent who presents with painless orolabial swelling may pose a diagnostic dilemma, and a thorough history and careful physical examination are of paramount importance. This swelling may be the presenting feature of disparate pathophysiologic processes including infections, irritant or allergic contact dermatitis, and systemic inflammatory diseases such as CD and sarcoidosis. When swelling becomes recurrent or chronic, a biopsy should be performed to aid in the diagnosis. One study found that 37% of patients who presented with features suggestive of oral CD had asymptomatic gastrointestinal involvement.⁶ If a child or adolescent has no history of CD but shows signs suggestive of a granulomatous cheilitis, further investigation and careful monitoring of the patient is recommended.