Rare, neuro-mucocutaneous disorder of unknown etiology
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Diagnostic triad (present in only 25% of cases):
- Oro-facial swelling, especially lip
- Relapsing facial nerve palsy (VII, V, VIII)
- Fissured tongue
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- Oligosymptomatic or monosymptomatic forms are more frequent than the full triad
- Most common monosymptomatic form: recurrent lip swelling (Miescher’s syndrome or Miescher’s chelitis granulomatosa) - 74% of cases
- Epidemiology
- Incidence: 0,08% in the general population
- Onset from early childhood to late adulthood
- As early as age 3 years
- As late as age 78 years
- More common in young adults (average age of onset 32 years)
- Orofacial herpes may precede onset
- Etiology
- Genetics - inconclusive data about link with HLA antigens and inheritance patterns for subsets of the disease
- Food allergy
- Food addictives may cause, trigger or exacerbate
- 60% are atopic (eczema + high IgE levels)
- Allergy to dental material - no conclusive evidence
- Infection - Mycobacterium tuberculosis, mycobacterium paratuberculosis, saccharomyces cerevisiae and Borrelia burgdorferi
- Immunological
- No single antigen incriminated
- Random influx of inflammatory cells
- Delayed hypersensitivity reaction rather than reaction to superantigen
- Clinical presentation
- The first episode of lip edema usually subsides completely in hours or days
- After recurrent attacks, swelling may persist and slowly increase, eventually becoming permanent
- Recurrences can occur after days to years
- Fissured tongue present since birth in some patients
- Loss of the sense of taste and decreased salivary gland secretion
- Attacks sometimes are accompanied by fever and mild constitutional symptoms (eg. headache, visual disturbances)
- Histopathology
- Histologic changes are not always conspicuous
- Needs to be incisional biopsy, not punch
- Infiltrate becomes denser and pleiomorphic
- Small, focal, noncaseating, epithelioid granulomas are formed (indistinguishable from Crohn disease or sarcoidosis)
- Small granulomas occur in the cervical lymph nodes
- Submucosal chronic lymphohistiocytic inflammation with many Th1 and mononuclear IL1 producing cells
- Large active dendritic B cells
- Inflammatory response probably mediated by TNF alpha and protease-activated receptors (PARs), matrix metalloproteinases (MMPs) and cyclo-oxygenases (COXs)
- Treatment
- Often unsatisfactory
- Indentification and avoidance of suspicious allegens
- Positive patch testing in up to 40%; half benefit from allergen exclusion
- Implementing a cinnamon and benzoate free diet helps 54-74% of patients
- Daily compression using specialized devices, potentially worn overnight, can reduce lip edema
- Intralesional corticosteroids: beneficial for some patients, particularly when used alongside with antibiotics, eg. oral metronidazole
- Oral corticosteroids (first line)
- Methotrexate and immunosuppresants (second line)
- Combination therapies:
- Intralesional pingyangmycin combined with dexamethasone reported anecdotally as effective
- Reduction cheiloplasty with intralesional triamcinolone; best results observed when combined with systemic tetracycline → prevention of recurrences
- Nerve decompression → effective for recurrent facial nerve palsy