Congenital Throat Problems

There are a range of congenital throat problems - some occurring alone and others as part of a syndrome. The underlying causes are varied but as with any congenital disorder, they can be broadly divided into chromosomal abnormalities (mutations and inherited problems), diseases associated with prenatal infection, maternal drug abuse, environmental factors, iatrogenic causes and abnormalities of unknown aetiology¹. The history will generally point you in the right direction and management will be guided by the degree of functional impairment as well as by any associated psychological distress associated with the condition (including parental when child is very young). These are generally uncommon conditions, occurring in < 5:10,000 births for each of ear, nose and throat abnormalities.

Laryngomalacia

Most common congenital laryngeal abnormality (60% of all cases, 2M:1F) where the larynx is soft and floppy and collapses during breathing. Infants present within the first few weeks of life (not necessarily at birth) with noisy respiration and inspiratory stridor which are worse in the supine position, when feeding or when agitated. These problems initially worsen with age but tend to resolve by 18-24 months. Respiratory distress, failure to thrive and cyanosis are rare. Most of these children are managed conservatively with close observation (with particular note taken of any reflux disease, known to be associated with this condition). Surgical intervention is only warranted with severe respiratory distress.

Laryngeal atresia

Also known as glottic atresia - this is absence of laryngeal lumen^{2 3}. This can occur at any level of the larynx and it represents the most extreme form of laryngeal webs. Rare abnormality (50 reported cases): prenatal diagnosis is imperative prenatally (not often possible) or at birth (severe distress on clamping the cord) as this is invariably fatal unless tracheostomy performed at time of birth. Often associated with other abnormalities, most commonly pulmonary hyperplasia but also problems in the CNS, GI, urogenital and skeletal systems.

Subglottic stenosis

Third most common congenital laryngeal abnormality³ (15% of all cases) and most common cause for performing tracheostomy in infants. Presents in the first few months of life with stridor ± respiratory distress during the course of an acute inflammatory process (e.g. URTI). Resembles croup but symptoms are recurrent and prolonged (>3 days). May be asymptomatic but may be reported that child is difficult to intubate. May be associated with Down's syndrome. Mild cases may resolve spontaneously as child grows but more severe cases require surgery (laser ablation therapy available for certain cases).

Laryngeal webs

These are fibrotic sheets of tissue representing incomplete canalisation of the larynx during development usually occurring between the vocal cords ³. The newborn will present with respiratory distress, stridor and a weak cry where the webs are thick and similar but less severe symptoms when they are thin or incomplete sheets (may be as little as mild dysphonia). “Sail sign” on lateral plain XRs (persistent tissue between vocal cord and subglottis) but definitive assessment is via rigid laryngoscopy. Management ranges from observation in very mild cases to surgery: incision may do for thin webs but excision is required with more substantial ones. Tracheostomy is performed in severe cases.

Laryngotracheoesophageal cleft

This rare midline defect⁴ involves the posterior larynx / trachea and the anterior wall of the oesophagus. Mild forms may present with stridor, coughing and cyanotic episodes precipitated by feeding but more extensive clefts may be fatal. Most commonly associated with cardiac and pulmonary abnormalities but ophthalmic and genitourinary problems also documented.

Laryngeal masses

Subglottal haematomas present between 2-12 months of age with croup-like symptoms of varying severity as well as failure to thrive. Most patients develop respiratory symptoms warranting tracheostomy until lesion regresses (usually by 5 years). Diagnosis is confirmed by rigid bronchoscopy.
Other masses include laryngeal cysts (rare; present with varying degrees of respiratory obstruction and dysphagia) and the equally rare lymphangioma arising from lymphatic vessel malformations. Upper respiratory tract infections are particularly prone to increase the size of lymphangiomas and may result in tracheostomy being performed. Laser ablation is carried out in less acute cases.

Congenital neuromuscular problems in the larynx

Congenital vocal fold paralysis is the second most common congenital laryngeal abnormality (15-20% of all cases). It is usually idiopathic but may be seen where there is neuromuscular immaturity or where there are CNS abnormalities (e.g. Arnold-Chiari malformation, cerebral palsy, hydrocephalus, myelomeningocoele, spina bifida, hypoxia or haemorrhage). Birth trauma can also cause paralysis for up to 9 months.

• Bilateral paralysis presents in the infant with varying degrees of respiratory distress who may have had recurrent chest infections secondary to aspiration.
• Unilateral paralysis may be asymptomatic or present with a hoarse cry and difficulty in feeding.

Diagnosis is with endoscopy and management depends of severity of symptoms (tracheostomy to simple observation). Nutritional support will also be considered in the child with bilateral paralysis.
Other neuromuscular problems relate to a number of syndromes: Cri-du-chat syndrome, Plott syndrome and arthrogryposis multiplex congenita.

Branchial malformations

Neck abnormalities^{2 3} can be traced back to the abnormal development of the branchial apparatus, which makes an appearance in the second week of embryonic life. This apparatus is made up of five pharyngeal arches (confusingly numbered 1-6, the 5th being lost in development) which give rise to muscular, skeletal, neural and vascular structures of the neck. If this complex process is disturbed, a cyst, sinus or fistula will result depending on the degree of development. Abnormalities of a structure in a given arch are likely to affect other derivatives from that same arch (e.g.: fistulae communicate between structures of the same arch). Evaluations of such abnormalities are carried out in a specialist unit.

Thyroglossal ducts / cysts

These are the most common abnormality of the neck: see separate article on thyroglossal cysts.

Haemangiomas

These are the most common of all congenital abnormalities: the incidence is 0.3-2% at birth and 10% at one year. They can be distinguished from vascular malformations: a haemangioma is a proliferative lesion whereas a vascular malformation is an abnormally formed vessel (distended vessel growth). A lesion may be both a haemangioma and a vascular malformation. The most common site of presentation for these lesions is in the scalp, face and neck.

Thymic abnormalities

Incomplete descent of the thymus into the chest can give rise to thymic cysts along the descent line and thymic cysts can be sequestered along the way so giving rise to ectopic tissue. These cysts can grow, become engorged or bleed, so giving rise to asymptomatic neck lumps, typically in the first decade of life (2/3 are diagnosed at birth).10% of patients will present with a mass effect dysphagia, dyspnoea, pain, hoarseness, in which case, surgery is warranted.
It is worth noting that thymic cysts can manifest themselves in association with a number of other conditions e.g. thyrotoxicosis, aplastic anaemia, Down's syndrome and Hodgkin's lymphoma. Uncommonly, myasthenia gravis can be associated with thymic cyst neoplasm.

Sternocleidomastoid tumour of infancy

A firm, painless neck mass presenting within first 2 months of life, more on the right and in males, particularly if born breech. Usually resolve by 6 months but follow up and appropriate physiotherapy is important to avoid craniofacial asymmetry (surgery may be indicated where torticollis does not resolve by 1 year).

Dermoid cysts

These are also seen (1/4 of these occur in the neck) as well as the rare cervical teratoma (often large and diagnosed at birth) and midline cervical cleft. Surgical excision / repair is warranted for all these conditions.

Lymphangioma

These present as a painless multilobulated cystic neck mass manifesting shortly after birth (90% are apparent by the age of two). These tend to enlarge during periods of infection and may haemorrhage. These are managed by surgical excision.