Noma (Cancum Oris)

Noma

Noma is a severe disfiguring gangrene of the mouth and face that begins as a gingival ulcer and spreads rapidly through the tissues of the mouth and face. Synonyms include cancrum oris and fusospirochetal gangrene. The word Noma originates from the Latin word nomē meaning corrosive ulcer, and from the **Greek nomḗ meaning spreading (of a fire or ulcer) emphasizing the rapid progression of the disease. Noma disrupts anatomic barriers and spreads through muscle and bone, resulting in gangrene that may involve the maxilla, the mandible, and extend to the nose and infraorbital margins

Global distribution is poorly understood, because:

• Some patients deliberately conceal the condition due to stigma
• Many patients reside in rural areas, hence reporting may be poor
• Most affected individuals succumb to the disease in the acute stage before presenting for clinical assessment

Incidence is highest in Sub-Saharan Africa; also occurs in Asia and Latin America. Young children (age 2-6 years) are the most commonly affected. The World Health Organization estimates the global incidence of noma to be around 100,000 to 140,000 new cases per year

Stages of noma

• Causative organisms
  • Noma is a polymicrobial infection associated predominantly with anaerobic organisms
  • Implicated microbes includes:
    • Fusobacterium necrophorum
    • Prevotella intermedia
    • Alpha-hemolytic streptococci
    • Pseudomonas spp
    • Actinomyces spp
    • Peptostreptococcus micros
    • Some viruses: herpes simplex, cytomegalovirus
• Risk factors
  • Poverty: A critical risk factor for noma, associated with additional risk factors including poor sanitation, poor oral hygiene, food insecurity and limited access to healthcare services, high prevalence of infectious diseases including HIV/AIDS, tuberculosis. Noma is often described as “the face of poverty”
  • Malnutrition: Increases susceptibility to infection. Also has been associated with increase in mouth anaerobes in presence or absence of overt oral pathology, particularly P. intermedia
  • Acute necrotizing gingivitis: Is the precursor of noma and hence an important risk factor. Characterized by pain, halitosis, ulceration of one or more interdental papillae, fever and lymphadenopathy
  • Antecedent infections and immunosuppressive conditions: Measles, malaria, HIV/AIDS, tuberculosis, T2DM, immunosuppressive therapy, other diseases of immunodeficiency e.g. SCID
• Pathogenesis
  • Not fully understood
  • Involves a combination of compromised host defenses and bacterial infection
  • Often starts as a minor oral infection e.g. gingivitis, creating a favorable environment for opportunistic bacteria proliferation
• Signs and symptoms
  • Small ulcer of the gingival mucosa → rapid spread to involve the surrounding jaw, lips and cheeks by gangrenous necrosis
  • Overlying skin is inflammed edematous and finally necrotic
  • Foul odor
  • Secondary infection e.g. pneumonia, sepsis
• Differentials
  • Noma neonatorum – Occurs during the first few weeks of life in premature and low birthweight infants, with the gangrene generally involving the oronasal region, eyelids, and perineum.
  • Ecthyma gangrenosum – A necrotic skin lesion caused by infection with  P. aeruginosa that may involve the oral cavity, nose, or perineum. Resembles noma histopathologically.
  • Mycobacterial infection –  Mycobacterium tuberculosis and Mycobacterium leprae infection may present with oral ulceronecrotic lesions.
  • Mucocutaneous leishmaniasis – Causes disfiguring destruction of the mucous membranes of the nose and mouth.
  • Oral and maxillofacial myiasis – Myiasis may cause a skin lesion resembling noma in adults and older children. Caused by deposition of tumbu fly larvae in subdermal tissue.
  • Necrotizing fasciitis – May involve the head and neck following an odontogenic abscess or trauma and may be associated with gangrene of the cheek.
  • Osteonecrosis of the jaw – Typically associated with medications such as bisphosphonates and generally occurs in adults in association with underlying malignancy.
  • Ludwig’s angina – Infection of the submandibular space that most commonly arises from an infected tooth in adults or children.
  • Oral tumors – Typically present as a nonhealing ulcer or mass.
  • Syphilis – In late syphilis, gummatous lesions may occur on the skin and present as ulcers or heaped-up lesions.
• Investigations
  • Swab for MCS
  • Facial X-ray and CT scan: to determine the extent of the lesion
  • Blood culture: if there are signs for sepsis
  • Complete blood count: for anaemia and leukocytosis
  • C-reactive peptide: elevated
  • Random blood sugar: for hypoglycemia
  • Liver function test: for hypoalbuminemia
• Principles of treatment
  • Antibiotic therapy
  • Wound care
  • Fluid and electrolyte replacement
  • Good nutrition
  • Oral physiotherapy
  • Reconstructive surgery
  • Counselling
  • Patient and caregiver education
• Treatment of Stage 1 – Acute necrotizing gingivitis
  • Amoxicillin PO 100 mg/ kg every 12 hours for 14 days + metronidazole PO 15 mg/ kg every 12 hours for 14 days
  • Mouthwash with Chlorhexidine 0.2%, 10 ml 3 times daily
  • Aspirin or paracetamol
  • Use compresses soaked in hydrogen peroxide 20 volumes to clean the gum lesions
  • Vitamin A supplements
  • Nutritional rehabilitation: high-energy high- protein diet, ready to use paste 3 sachets/daily
• Treatment of Stage 2 – Edema
  • This and all subsequent stages should be treated as emergencies, with immediate referral to the nearest hospital
  • Antibiotic treatment
    • Option 1: Amoxicillin & clavulanic acid, 50 mg/ kg intravenously every 6 hours for 14 days + slow intravenous administration of gentamicin, 5 mg /kg every 24 hours for 5 to 7 days + slow intravenous administration of metronidazole, 15 mg/ kg every 12 hours for 14 days
    • Option 2: Ampicillin intravenously, 100 mg/ kg every 6 hours for 14 days + slow intravenous administration of gentamicin, 5 mg/ kg every 24 hours for 5 to 7 days + slow intravenous administration of metronidazole, 15 mg /kg every 12 hours for 14 days
  • Mouthwash with Chlorhexidine 0,2%, 10 ml 3 times daily
  • Correct dehydration and electrolyte imbalance
  • Nutritional rehabilitation
  • Correction of anemia with folic acid, iron, ascorbic acid and vitamin B
  • Treatment of underlying conditions: measles, malaria, TB, HIV, diarrheal diseases
• Treatment of Stage 3 – Gangrenous
  • Treatment of lesions: regularly bathe the lesions with an antiseptic, cover the cavities with gauze compresses soaked in antiseptic, keep the compresses moistened by further dousing their external layers with solution
    • Honey may be used for local dressing, anti-bacterial action and regeneration
    • IM ketamine may be used during dressing
  • If the patient’s condition permits, rinse out his/her mouth daily with chlorhexidine digluconate solution as in stage 2
  • Administration of high doses of antibiotics: as in stage 2
  • Correct anemia with folic acid, iron, ascorbic acid and vitamin B
  • Treatment of any underlying conditions
  • Nutritional rehabilitation, preferably orally, or by parenteral administration, or by nasogastric intubation if the patient is severely weakened
  • Correction of dehydration and electrolyte imbalance
  • Deworming
  • Management of secondary hemorrhage
• Treatment of Stage 4 – Scarring
  • Antibiotic treatment, wound care and mouthwash as in stage 2 and 3
  • Oral physiotherapy – in order to preserve the mouth opening
  • Removal of all the scabs and exeresis of necrotic tissue
  • Extraction of all loose teeth
• Treatment of Stage 5 – Sequelae
  • Surgical correction of trismus with postoperative physiotherapy to prevent the recurrence. Additional surgical intervention may include tissue flaps and/or bone grafting
  • Psychosocial assistance to promote social reintegration
  • Major reconstructive surgery (only carried out when the acute phase of noma is completely over and the progression of the disease has been definitively halted to allow time for resolution of necrosis)
  • Once patient recovers his/her functional capacities and is free of trismus, aesthetic rehabilitation may commence (may be months or years later)
  • Antibiotics are not needed at this stage as the acute phase is over
• Prevention
  • Requires a multidisciplinary approach with attention to routine health care needs, sanitation, nutrition, vaccination, and public awareness.
  • Measures include:
    • Health education about risk factors for and early signs of noma
    • Regular screening of at risk children
    • Teaching of proper oral hygiene practices
    • Routine immunisation
    • Proper sanitation
    • Adequate nutrition
• Complications
  • Dehydration
  • Sepsis
  • Airway compromise
  • Facial disfigurement
  • Psychological stress