Epiglottitis is an acute inflammation and swelling of the epiglottis (a flap of cartilage at the base of the tongue that prevents food from entering the airway). It is a medical emergency because swelling can rapidly block the airway. (Mayo Clinic)
Anatomy and Function of Epiglottis
Located above the larynx.
Acts like a “lid” over the trachea during swallowing.
Prevents aspiration of food and liquids into the lungs.
Causes
Infectious Causes
Haemophilus influenzae type b (Hib) – classic cause in children
Gowers’ sign is a medical sign that indicates weakness in the pelvic girdle and proximal lower limb muscles. It’s characterized by a patient using their hands to “walk” up their body to get to a standing position.
Duchenne Muscular Dystrophy (DMD) is the most common and severe form of progressive muscular dystrophy in children. It belongs to a group of primary myopathies characterized by a progressive, genetic-based degeneration and death of muscle fibers.
1. Genetic Profile and Pathogenesis
Inheritance: DMD is an X-linked recessive disorder, almost exclusively affecting males and carried by females. Approximately one-third of cases result from de novo (new) mutations.
Molecular Defect: It is caused by a mutation (typically a deletion) in the gene for dystrophin located on chromosome Xp21.
Mechanism: Dystrophin is the longest known human gene and encodes a protein that connects the muscle fiber cytoskeleton to the surrounding extracellular matrix. Without functional dystrophin, muscle cells undergo chronic damage, necrosis, and replacement by fat and fibrous tissue.
2. Clinical Features
DMD typically presents between the ages of 2 and 5 years.
Early Signs: Delayed motor milestones (especially late walking) and mild speech or language delay are often the first indicators.
Muscle Weakness: Progressive, symmetric weakness begins in the pelvis and hip girdle, later involving the shoulder girdle.
Gait and Mobility: Affected children exhibit a waddling (Trendelenburg) gait, frequent falls, and difficulty climbing stairs (mounting them “one by one”).
Gower Sign: A classic clinical finding where the child, unable to stand up normally from the floor, must turn prone and “climb up his own thighs” with his hands to reach an upright position.
Pseudohypertrophy: Striking enlargement of the calf muscles occurs because muscle tissue is replaced by fat and connective tissue rather than true muscle growth.
Intellectual Function: Approximately 20% to 30% of boys have learning difficulties or non-progressive intellectual impairment.
3. Diagnostic Evaluation
Diagnosis should be initiated at the first clinical suspicion.
Serum Creatine Kinase (CK): Remarkably high levels (usually 10 to 40 times normal) are a hallmark of the disease.
Genetic Testing: Direct dystrophin gene testing is now the preferred definitive method and often avoids the need for a muscle biopsy.
Electromyography (EMG): Shows a “myopathic” pattern, including reduced amplitude and duration of motor unit potentials.
Muscle Biopsy: If performed, shows fiber necrosis, phagocytosis, and increased endomysial fat and connective tissue.
4. Progression and Complications
Loss of Ambulation: Most boys become wheelchair-bound by age 10 to 13.
Orthopedic: As weakness progresses, many develop scoliosis, particularly once they are no longer walking.
Cardiac: Progressive cardiomyopathy and persistent tachycardia develop in nearly all patients.
Respiratory: Weakness of the diaphragm and intercostal muscles leads to nocturnal hypoxia and eventual respiratory failure.
Prognosis: Death typically occurs in the late teens or 20s from cardiorespiratory complications.
5. Management
Management requires a specialist multidisciplinary team.
Corticosteroids: (e.g., Prednisone or Deflazacort) are the mainstay of treatment, as they preserve mobility, improve muscle strength, and prevent scoliosis.
Supportive Care: Physiotherapy and splinting are used to prevent contractures. Nocturnal hypoxia may be managed with overnight CPAP.
Novel Therapies: Research into exon-skipping drugs (e.g., Ataluren or Eteplirsen) allows for the production of small amounts of functional dystrophin in patients with specific mutations.
Genetic Counseling: Crucial for the family to detect female carriers and discuss antenatal diagnosis.
DMD vs. Becker Muscular Dystrophy (BMD): BMD is a milder allelic variant where some functional dystrophin is produced. BMD features a later onset (average 11 years), a slower course, and patients typically remain ambulatory into their late 20s or beyond, with many living into middle age.
