Achalasia is a rare entity in the pediatric population. It is estimated to affect between 0.11 and 0.18/100,000 children annually [1, 2]. It can occur as young as 7 weeks of age, but children under 15 years of age account for less than 5 % of all achalasia cases [3–6]. As in adults, pediatric achalasia is most commonly idiopathic and isolated; however, it occurs infrequently in the setting of genetic and familial conditions. Symptoms of vomiting, progressive dysphagia, and weight loss are a result of failure of relaxation of the lower esophageal sphincter (LES), impaired peristalsis, and increased LES resting pressures [7, 8]. Diagnosis and treatment are similar to adults, with no curative treatment available, but a number of different options for symptom palliation.

For the majority of children with achalasia the pathophysiology is the same as adults, with some histologic studies suggesting an autoimmune component [9], but children may also develop this in the setting of genetic conditions. Familial achalasia is extremely rare, with case reports of parent and child with achalasia and multiple siblings from consanguineous relationships affected suggesting an autosomal recessive inheritance [10–13]. Genetic analysis of one set of siblings demonstrated a mutation in nitric oxide synthase, requiring sildenafil treatment after failure to improve with cardiomyotomy [11]. Achalasia may also occur in the setting of multiple syndromes including Allgrove’s syndrome, Sjogren’s syndrome, Rozychi’s syndrome, and Down’s syndrome [14–16]. Since Allgrove’s first description of patients with achalasia, alacrima, and adrenal insufficiency in 1978, there have been multiple reports of patients with Triple A syndrome [16]. Also known as Allgrove syndrome or 4A syndrome (including autonomic disturbance), children may present first with achalasia, necessitating careful clinical evaluation for signs of hyperpigmentation and abnormal lacrimation that may allow treatment before life-threatening complications of adrenal insufficiency develop [10, 17, 18]. There is no consensus as to the optimal therapy for patients with Triple A syndrome, but multiple reports show improvement with esophageal cardiomyotomy with or without partial fundoplication [10, 19]. Heller’s myotomy has also been successful for the rare children who develop achalasia in the setting of Down’s syndrome [3, 14]. One recent series of three pediatric achalasia patients suggests a possible association with autism, highlighting the need for evaluation of autistic children suffering from eating disorders or esophageal symptoms with barium swallow and manometry [20].

The rarity of achalasia and presence of symptoms that mimic common pediatric diagnoses may lead to misdiagnosis in children with this disease. Achalasia symptoms often mimic those of gastroesophageal reflux disease (GERD) in younger children who present with failure to thrive, feeding difficulties, and recurrent pneumonia [5, 21]. This atypical presentation can lead to a delay in diagnosis anywhere from a few months to more than 5 years [5]. Confounding the picture, GERD has also been reported in some series to accompany or precede achalasia, leading to recommendations to consider high-resolution manometry (HRM) in those children who do not respond to initial reflux treatment [22]. Given the relative frequency of GERD compared to achalasia, up to 50 % of children are treated with prokinetic or antacid medications prior to receiving a definitive diagnosis of this condition [5, 7]. A study of Brazilian children revealed that many patients are misdiagnosed with asthma, with 46 % of those eventually diagnosed with achalasia receiving ineffective asthma therapy for chronic cough that resolved with esophageal myotomy or pneumatic dilation [5]. In three children thought to have refractory asthma, the diagnosis was only suspected once tracheal obstruction was identified on pulmonary function testing, leading to further work-up with diagnosis and successful treatment of their achalasia [23–25]. Achalasia can also be confused with eosinophilic esophagitis, with one study reporting elevated intraepithelial eosinophils in 34 % of patients, and 8 % meeting criteria for eosinophilic esophagitis [26]. Common symptoms have also contributed to multiple reports of adolescents and children diagnosed and treated for eating disorders, (both anorexia nervosa and bulimia) who were eventually diagnosed and successfully treated for esophageal achalasia [5, 27, 28]. These highlight the need to fully evaluate children with dysphagia, even if symptoms suggest a psychiatric etiology.

Importantly, esophageal dysmotility and distension have been misdiagnosed as achalasia in multiple adolescents who were eventually diagnosed with an H-type trachea-esophageal fistula [29–31]. H-type fistulas can cause chronic over-distension of the esophagus and affect peristalsis, leading to the diagnosis of achalasia, but not necessarily requiring any other treatment once the fistula is closed [31].