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How to Recognize the Medical Comorbidities of Autism

October 9, 2023

How to Recognize the Medical Comorbidities of AutismThe etiology of autism, though still a mystery, is believed to be a combination of genetic and environmental factors.  Autism is thought to develop sometime during pregnancy and the first three years of life (early-onset autism) or, as in regressive or late-onset autism, some children appear to have developed normally until 12-24 months before losing skills.

Autism has historically been considered a neurodevelopmental or psychiatric disorder, as classified in the DSM-V.  However, current research is pointing to many underlying medical issues, involving the gut and the immune system, which may affect treatment protocols and may also exacerbate the behavioral symptoms and cognitive deficits.  As our understanding of these medical comorbidities increases, so must our awareness of the symptoms at all ages—most importantly, in infancy. Early identification of the medical red flags increases the likelihood of proper intervention, which can prevent chronic health issues and decrease maladaptive behaviors, improving the quality of life.

In children with ASD, these early medical and developmental signs often present in clusters but can be very difficult to recognize. Symptoms can easily be misunderstood and therefore may be overlooked by parents and underreported to physicians.  Additionally, since some of the symptoms can be episodic, a physician is unlikely to observe them in a well-baby visit, thereby decreasing the chance of further evaluation.

So what are these early medical signs and symptoms and what should you do if you suspect your child may exhibit them?

Medical Red Flags


According to The National Institute for Neurological Disorders and Stroke, about 20-30% of individuals with autism will develop epilepsy by adulthood. Frequently, young children with autism have subclinical seizures, which have no symptoms.  Symptoms of simple partial seizures may be mild, such as eye-gaze, aura’s, a brief increase or decrease in muscle tone, or unusual sensations affecting the five senses.  It is easy then to understand how these symptoms may be overlooked in a young child by both parents and physicians.

If you have concerns that your child may exhibit any of these signs or other signs of seizures, it is best to speak to your pediatrician and ask for a referral to a pediatric neurologist.

Gastrointestinal Disorders

GI disorders are the most common comorbid medical condition of autism.  Studies show that 70% of children with ASD have some type of gastrointestinal disorders that can include:

  • GERD (gastroesophageal reflux disease)
  • Constipation
  • Irritable bowel
  • Motility issues
  • Gastritis

GI disorders in children with ASD are often difficult to recognize and treat due to communication impairments. Infants, still unable to communicate, are particularly difficult to diagnose.  Early signs of gastrointestinal distress can be observed in the irregularity of bowel movements, diarrhea, or constipation.  It is important to note that reflux in infants does not have to be “seen” as spit-up to be present. Reflux is also exacerbated when lying down; therefore, infants who have trouble sleeping can be showing signs of GERD.

Watch your child for an increase in behaviors that can include applying pressure on the abdomen, leaning over furniture to press on the belly, and hitting the sides, chest, or chin.  Often these behaviors are misinterpreted as self-injurious behaviors when actually they are an indication of GI pain or reflux.

Talk to your pediatrician about symptoms; however, if GI symptoms persist, ask for a referral to a pediatric gastroenterologist.

Food Allergies and Sensitivities

Research suggests that 36% of children with ASD have food allergies.  Allergies are an inflammatory response of the immune system to defend the body against irritants.  Allergies can be genetic, especially in families that tend to have a history of eczema, asthma, and seasonal allergies. Food allergies can cause gastrointestinal issues as well as irritability and pain, which could exacerbate behavioral responses.

According to Dr. Raffi Tachdjian, Allergy/Immunologist of The Autism Think Tank, NJ, “Early signs of food allergies in infants can be bloody stools, vomiting, diarrhea, fussy or erratic behavior, and arching of the back.  After one year of age, swelling and hives can develop.” Children with ASD are commonly reactive to cow’s milk (casein) and wheat, nuts, eggs, and soy; however, allergy testing should be considered across a broad spectrum of allergenic foods if allergy or sensitivity is suspected.

A consultation with a board-certified allergy/immunologist is recommended if you suspect food allergies.

Eczema, an atopic dermatitis, most often has an allergy basis and is very common in children with ASD. Children with eczema frequently have food allergies, and food triggers can cause flare-ups. Dr. Tachdjian says, “Much like a nickel or make-up allergy, eczema can have an immediate or delayed response and throw a parent off by not correlating in time with a possible food trigger.” Eczema causes itching and discomfort, so it is important to consult your pediatrician if you notice eczema patches on your child.

If eczema spreads or flare-ups are noted in response to certain food triggers, it is best to consult with a pediatric allergy/immunologist.

Although many of these “red flags” can be seen in the neurotypical child, it is the timing and combination of these symptoms that can be cause for concern. Essentially, this is the very reason why making an early diagnosis is so very difficult to do.  Parents should be aware of the most common developmental signs and medical comorbidities so they can describe behaviors and symptoms to pediatricians and medical specialists.

Always consult your pediatrician and ask for referrals to specialists such as neurologists, allergy/immunologists, gastroenterologists, speech and language pathologists, and occupational and physical therapists. Early intervention is imperative for a positive prognosis.

Ear Infections

While research shows only a slightly higher risk, parents frequently report their child with ASD had frequent bouts of ear infections. Ear infections can be a weakness of the immune system referred to as immunodeficiency. Frequent ear infections can cause speech and language delays, as speech sound frequencies cannot be perceived normally.  Signs of ear infections in infants can include irritability, poor appetite, and sleeplessness.  It can also cause physical symptoms such as red ears, vomiting, and diarrhea. Children with ASD may not perceive pain the same way as neurotypical children and may not show behavioral signs such as irritability or crying from pain. Therefore, it is important to recognize the physical signs.

If your infant or young child has frequent ear infections, ask your pediatrician for a referral to an immunologist and ear, nose, and throat specialist.

It is critical that attention is given to early markers that could help identify the vulnerable child who may have compromised immune systems, allowing parents and physicians to limit further environmental exposures while also tracking the development.  Autism is a medically complex disorder; therefore, early recognition of both the developmental red flags and the associated medical complications could improve overall outcomes.

This article was featured in Issue 53 – Working Toward The Future

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