However, in children, due to their thicker septum and more flexible lining, nasal septal hematoma can be caused from minor nasal trauma such as simple falls, collisions with stationary objects, or minor altercations with siblings. Mechanism and pathophysiology
The exact mechanism for the formation of hematoma from nasal trauma is controversial, but thought to occur in nasal septal hematomas when there is force to the nasal cartilage. The force causes the perichondrial blood vessels to leak and rupture in the nasal septum. The cartilage in the septum is avascular and can be 2–4 mm thick. The septum gets its blood supply from the ethmoid and sphenopalatine arteries.The nasal septum is composed of cartilaginous, membranous, and bony components overlaid by mucoperichondrium and mucoperiosteum. Bleeding within the confines of the mucoperichnondrium leads to a septal hematoma, where as external bleeding from Kiesselbachs plexus results in epistaxis. The Kiesselbach plexus is located anterior inferior of the nasal septum, where the anastomosis of blood vessels is located.Normal nasal mucosa is pink and healthy appearing, without ulcerations, crusting, or bleeding. Some common, abnormal variations include septal deviations, spurs, and an enlarged, aerated middle turbinate. Pale or inflamed mucosa, purulence, nasal polyps, or a septal perforation are all common pathologic features that may or may not be combined with the abnormal variations listed above. Diagnosis
The doctor will use a nasal speculum for visualization of the nasal septum, the inferior turbinate, and a portion of the middle turbinate. The view of the nasal passage may be partially obstructed by the tools used.
Although occasionally preceded by and/or associated with vesicle formation, it is always associated with a juxta-epithelial inflammatory reaction followed by a fibroelastic change of the lamina propria with epithelial atrophy leading to stiffness of the oral mucosa, progressive decrement in mouth opening and inability to eatPer Chandramani More and Naman Rao (2019) (Clinical definition)-
A debilitating, progressive, irreversible collagen metabolic disorder induced by chronic chewing of areca nut and its commercial preparations; affecting the oral mucosa and occasionally the pharynx and esophagus; leading to mucosal stiffness and functional morbidity; and has a potential risk of malignant transformation. Epidemiology
The incidence of the disease is higher in people from certain parts of the world including South and South East Asian, South Africa and the Middle Eastern countries. Symptoms
In the initial phase of the disease, the mucosa feels leathery with palpable fibrotic bands. In the advanced stage the oral mucosa loses its resiliency and becomes blanched and stiff. The disease is believed to begin in the posterior part of the oral cavity and gradually spread outward. Other features of the disease include: 

Xerostomia
Recurrent ulceration
Pain in the ear or deafness
Nasal intonation of voice
Restriction of the movement of the soft palate
A budlike shrunken uvula
Thinning and stiffening of the lips
Pigmentation of the oral mucosa
Dryness of the mouth and burning sensation (stomatopyrosis)
Decreased mouth opening and tongue protrusion

Causes
Dried products such as paan masala and gutkha have higher concentrations of areca nut and appear to cause the disease.