PANS/PANDAS and Eating Disorders

Restricted eating in PANSPANDAS Clinical Features, differential diagnosis, & treatment aspirePANS/PANDAS and Eating Disorders

Restricted eating is one of the two primary diagnostic criteria for Pediatric Acute-onset Neuropsychiatric Syndrome (PANS), yet its presentation can vary considerably from one patient to another. An individual may suddenly fear choking or vomiting, become convinced that food is contaminated, lose interest in eating, develop intense sensory aversions, restrict foods according to specific characteristics or rituals, or develop concerns about weight and body image. In severe cases, food and fluid restriction can result in significant weight loss, dehydration, malnutrition, medical instability, and hospitalization.

These symptoms can overlap substantially with eating disorders, particularly Avoidant/Restrictive Food Intake Disorder (ARFID) and Anorexia Nervosa (AN). Some patients with PANS/PANDAS may also meet diagnostic criteria for an eating disorder. Understanding that overlap is important. The presence of ARFID, AN, or another eating disorder diagnosis does not necessarily explain the cause of the restricted eating or the broader clinical presentation.

Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) is characterized by the sudden onset or sudden worsening of obsessive-compulsive symptoms (OCD) and/or eating restrictions occurring alongside symptoms from at least two additional neuropsychiatric categories. These may include anxiety, emotional lability or depression, irritability or aggression, developmental regression, deterioration in school performance, motor or sensory abnormalities, and somatic symptoms such as sleep disturbances or urinary changes.

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) is a subset of PANS associated with group A Streptococcus (GAS). PANS may occur following other infections or inflammatory triggers. Following an infection such as strep, COVID-19, influenza, or a tick-borne infection, an individual may experience a distressing transformation marked by newly emerging or dramatically worsening anxiety, restrictive eating, phobias, rituals, mood changes, irritability, tics, separation anxiety, cognitive changes, and other neuropsychiatric symptoms. A once cheerful, sociable individual might inconsolably pace in circles for hours, compulsively wash their hands until they bleed, plead for relief from the torment within their mind, or refuse food because of fears of contamination or choking. These changes can leave both the affected individual and family struggling to understand what has happened. 1, 2, 17

Because many of the most visible symptoms are psychiatric or behavioral in presentation, individuals with PANS/PANDAS may initially be diagnosed with a primary psychiatric condition without consideration of a possible underlying medical disorder. This is particularly relevant when restricted eating is prominent because the presentation may resemble ARFID or AN. The clinical picture, however, extends beyond the eating symptoms alone. The timing and pattern of onset, associated neuropsychiatric and somatic symptoms, disease course, and relationship to infection or inflammation may provide important diagnostic information. 1, 9, 12

Correct diagnosis is important because it informs treatment. Eating restriction itself must be taken seriously and treated according to the patient’s medical and nutritional needs, regardless of its cause. At the same time, when restricted eating occurs as part of PANS/PANDAS, treatment may also need to address the underlying infection, inflammation, or immune dysfunction contributing to the broader illness.

Awareness of this intersection is particularly important as eating disorders have increased at alarming rates, including among populations in which they have historically been less frequently recognized. Hospitalizations for children under age 12 with eating disorders rose 119% between 1999 and 2006. It has been hypothesized that some of the increase, particularly among males, may be linked to PANS. If so, these patients require medical as well as psychiatric treatments to recover. Clinicians should be educated about the connection between restricted eating and neuroinflammation so they can make the correct diagnosis and prescribe appropriate interventions. Treatment with antibiotics or immunomodulatory therapies is often curative, making it doubly important to correctly diagnose these patients and provide appropriate treatment. 9, 12

PANS/PANDAS: Definitions and Diagnostic Overview

PANS is defined as the sudden onset or sudden worsening of obsessive-compulsive symptoms (OCD) and/or eating restrictions at the same time as symptoms from at least two out of seven distinct neuropsychiatric categories described below. There is no age requirement for a PANS diagnosis; symptoms typically start before puberty, but patients can have an initial onset after adolescence. In addition to infections, PANS symptoms can be triggered by non-infectious factors like metabolic disturbances and other inflammatory reactions. 1, 3, 7, 8, 11, 15

PANDAS is a subset of PANS, characterized by a sudden onset or worsening of tics or OCD, along with other neuropsychiatric symptoms seen in PANS, triggered by recent exposure to a group A Streptococcus (GAS) infection, such as strep throat or scarlet fever. 1, 2, 3, 4, 5

PANS/PANDAS are clinical diagnoses. Proper diagnosis does not depend on a single lab test or scan. Instead, diagnosis involves a thorough analysis of the individual’s medical and family history, a physical examination, an assessment of presenting symptoms, a psychiatric evaluation, and an evaluation for immune dysregulation when indicated. 1, 7

Such a comprehensive evaluation is necessary because PANS/PANDAS are diagnoses of exclusion, meaning that no other medical diagnosis better explains the symptoms. Disorders in the differential diagnosis include Sydenham chorea, autoimmune encephalitis, systemic autoimmune diseases, and Wilson’s disease. 1, 7, 12, 19

Because there is evidence of genetic susceptibility, a family history of mental health issues does not mean a PANS diagnosis should be ruled out. In fact, first-degree relatives of PANS/PANDAS patients often have higher rates of tic disorders, OCD, and acute rheumatic fever, which is a strep-triggered autoimmune disorder. During assessment, it is important to consider siblings and other relatives who had or have neuropsychiatric disorders, as they may provide clues about genetic susceptibility. Mothers of PANS patients often have autoimmune diseases. 1, 6

PANS Symptoms and Severity

By definition, PANS requires OCD and/or restricted eating. The OCD can include intrusive themes such as perfectionism/being “just right,” ordering, symmetry, contamination, sexual or religious thoughts, collecting, or hoarding. Restrictive eating can relate to obsessions with the texture of food, a fear of choking, vomiting, or contamination from specific foods, or anorexic behavior.

In addition to OCD and/or restrictive eating, the individual must exhibit at least two of the following seven categories: (1) anxiety, including separation anxiety, (2) emotional lability or depression, (3) irritability, aggression, rage and/or severe oppositional behaviors, (4) behavioral (developmental) regression, (5) deterioration in school performance, including decline in arithmetic abilities and deterioration of handwriting/drawing, (6) motor or sensory abnormalities, and (7) somatic signs, such as sleep disturbances or enuresis.

Symptom severity can range from mild to severe. In mild cases, individuals might function well enough to continue to attend school or other daily activities. In severe cases, symptoms can become life-threatening due to extreme food restriction, impulsivity, and/or suicidality. 1, 9, 12–15

Comprehensive details about diagnosis can be found in Clinical Evaluation of Youth with Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS): Recommendations from the 2013 PANS Consensus Conference. The PANDAS Physicians Network (PPN) has created flowcharts for diagnosis and treatment to assist clinicians in diagnosing and determining the best course of treatment. These guidelines and workflows were approved by practitioners of the PANDAS Physicians Network Scientific Advisory Board. 7, 19

PANS/PANDAS and Restrictive Eating Symptoms

Characterization of Restricted Eating in PANS/PANDAS

About 50% of PANS patients are reported to have food restriction symptoms. Approximately 1/3 of these patients will have significant impairments as a result, including unacceptable amounts of weight loss, dehydration, and malnutrition. In severe cases, patients may require hospitalization for intravenous fluid replacement, tube feedings, or other life-saving interventions. In one study, ten of forty-three patients met the criteria for ARFID and had significant impairments due to their restricted eating, including dehydration, weight loss, and hospitalizations. Ten patients also met the requirements for food-related OCD. Within this research cohort, those with restricted eating had higher rates of mydriasis (dilated pupils), tics, and choreiform (irregular, involuntary) movements. 5

Common Restrictive Eating Themes in PANS/PANDAS 5, 7, 9, 10, 18
  • Selective Eating
    • Obsessions with food type, order of eating, texture, taste, pattern, or color
    • Sometimes related to sensory issues
    • Severe picky eating, aversion to selected food types
  • Contamination, OCD-related
    • Contamination fears with a focus on germs, toxins, and/or poison
  • Appetite
    • No interest in food: no hunger, poor appetite, early satiety
  • Swallowing/Vomiting, may be related to OCD and/or sensory sensitivities
    • Fear of vomiting, choking, or swallowing, including their saliva
    • Dysphagia, the feeling of something stuck in the throat
    • Compulsions of spitting up, gagging, hoarding saliva, etc.
  • Body Image
    • Body image distortions, fear of weight gain or weight loss
PANS/PANDAS and Comorbid Eating Disorder Diagnoses 5, 7, 9, 10
  • ARFID is the most common comorbid eating disorder diagnosis in PANS/PANDAS, as patients have a clear eating disturbance resulting in inadequate food intake. Some have weight loss, and some have significant psychosocial dysfunction. It is not inappropriate to assign both a PANDAS or PANS and ARFID diagnosis as a means of providing comprehensive care to the affected individual.
  • AN is a possible comorbid diagnosis, typically occurring only after the patient has lost 10–15% of their body weight due to eating restrictions that are not initially associated with body image distortions. Obsessional fears in PANS and PANDAS may mirror those seen in AN, including fears of being overweight or having unattractive parts of their body. The correct diagnosis, or assignment of dual diagnoses, will depend on the rationale provided for the observed behaviors and the more extensive symptom profile.
  • Patients are unlikely to meet the criteria for Binge Eating Disorder (BED), but some individuals develop compulsive eating patterns, which can include excessive food intake.
How PANS/PANDAS Differs from Other Eating Disorders

While there is an intersection in symptomology between PANS/PANDAS and eating disorders such as AN and ARFID, there are foundational differences that warrant recognition. Awareness of these distinctions can help parents, patients, and medical professionals determine when further evaluation for PANS/PANDAS may be warranted. If PANS/PANDAS is suspected in a child or adult patient, consulting a healthcare specialist in this area is essential.

Differentiating Factors:
  • Onset: Symptoms of PANS/PANDAS typically have an abrupt onset or rapid escalation. In contrast, the onset of AN has an insidious onset. ARFID is typically an acute onset but can develop after a period of picky eating. 7, 9
  • Disease Course: PANS/PANDAS symptoms typically relapse and remit with periods of symptom exacerbation followed by periods of relative improvement unless the disease course has become static or chronic. This episodic pattern of symptoms is not typically seen in AN or ARFID. With timely and appropriate treatment, PANS/PANDAS symptoms, including restricted eating, can remit fairly quickly. The recovery rate from AN is typically slow, relapse is common, and there is a high mortality rate. The recovery rate from ARFID is also slow, and comorbidities must be addressed. 9, 12–15
  • Association with Infections: Infections often trigger PANS/PANDAS. In contrast, AN and ARFID are not directly linked to infection. 1, 5, 7, 9, 10
  • Presence of Additional Neuropsychiatric Symptoms: There are some key distinctions between PANS/PANDAS symptoms and the clinical presentations of ARFID and AN. While anxiety and OCD may manifest in all three conditions, PANS/PANDAS often involves additional symptoms not commonly seen with ARFID or AN. These symptoms include, but are not limited to, irritability, aggression, behavioral regression, decline in academic performance, tics or movement abnormalities, sensory issues, hallucinations, increased urinary frequency, and disturbances in sleep patterns. 1, 5, 7
  • Prevalence:
    • Anorexia: Females >> Males
    • ARFID: Females = Males
    • PANS disordered eating: Females < Males
    • PANS anorexia: Females > Males 9, 10

Health Consequences of PANS/PANDAS

Early identification and access to timely, appropriate treatment are paramount. Delayed or lack of treatment can possibly lead to neural injury, developmental disruption, inappropriate psychiatric medications, unnecessary psychiatric placements, years of needless suffering, and an increased risk of suicide. 12–15

Consequences of Not Treating PANS/PANDAS Symptoms

Early and continued treatment leads to better outcomes and fewer relapses compared to no treatment or delayed treatment. Medical, psychological, and behavioral interventions can decrease impairments and improve symptoms, making it crucial to begin treatments as soon as PANS/PANDAS is diagnosed. PANS/PANDAS symptoms, after the initial onset or acute flare, typically follow a relapsing-remitting course in which symptoms exacerbate upon exposure to a new trigger and gradually resolve with appropriate treatment. However, in some cases, symptoms can become chronic-static, where symptoms do not improve, or chronic-progressive as symptoms worsen over time. These patients require more intensive intervention. If intensive interventions become ineffective, a rehabilitative treatment approach may be necessary. 12–15

Consequences of Not Treating Restricted Eating Symptoms in PANS/PANDAS

Health consequences specifically related to PANS-related restricted eating patterns can mirror those seen in ARFID and anorexia nervosa. Individuals who significantly limit food intake may lose weight and experience consequences of starvation, including changes in heart rate or blood pressure, malnutrition, dehydration, weight loss and/or vomiting, and electrolyte imbalances, which can cause cardiac arrest or death. Highly selective diets that avoid many foods or categories, such as fruits, vegetables, and proteins, risk serious nutrient deficiencies that lead to downstream health problems. Medical instability increases with more extreme or prolonged restriction of food/fluids, greater weight loss, or more rapid weight loss. 10

Please see NEDA’s sections on ARFID and AN for comprehensive details about those diagnoses.

  • ARFID
  • Anorexia nervosa

PANS/PANDAS Three-Pronged Treatment Overview

PANS is thought to result from various disease mechanisms and multiple etiologies. These range from psychological trauma or underlying neurological, endocrine, and metabolic disorders to post-infectious autoimmune and neuroinflammatory disorders. 80% of PANS patients present with neuroinflammation and/or post-infectious autoimmunity. Consequently, PANS treatment utilizes three complementary interventions.

The three-pronged approach utilizes psychiatric medications when appropriate to provide symptomatic relief, antimicrobial treatments to eliminate the source of neuroinflammation, and anti-inflammatory and immune-modulating therapies to treat disturbances of the immune system. 12–15, 19

  • Remove Inflammatory Sources: antimicrobial treatments for infectious triggers; non-infectious triggers require other interventions.
  • Treat Immune System Dysregulation: anti-inflammatories such as NSAIDs or steroids, and/or immunotherapies.
  • Treat Symptoms: psychoactive medications, psychotherapeutic interventions, and supportive therapies.

Providers must individualize treatment protocols according to the patient’s severity of symptomology, course of illness, lab testing, and physical exam. Primary care providers can treat most PANS patients in accordance with the Treatment Guidelines and the PANDAS Physician Network’s Treatment Flow Charts. Severe or complex patients may require a multidisciplinary team of PANS clinicians.

Treating Symptoms

Psychological, behavioral, and psychopharmacologic interventions tailored to each patient’s presentation can relieve symptoms and improve functioning during the acute and chronic stages of illness. Typically, evidence-based interventions are appropriate for a range of symptoms. Mild to moderate symptoms may not require pharmacological intervention, while more severe or chronic symptoms may necessitate behavioral therapy, further education, and pharmacologic treatments. Psychiatric medications, generally, should be implemented with a “start low & go slow” approach; beginning dosages for PANS are often ¼ or less than typical doses. Some patients respond quickly and positively to medical interventions, while others experience fewer positive outcomes. Thus, mental health providers should avoid quick changes with each symptom shift. During the acute phase, due to neuroinflammation and the overwhelming severity of symptoms, the patient may not be ready to participate in Cognitive Behavior Therapy (CBT), Exposure and Response Prevention Therapy (ERP), and other behavioral therapies until medical treatments take effect. During this time, parents can learn to limit the accommodation of behaviors and fears. 12, 13, 19

Treating Immune System Dysregulation

Immune treatments are used only in PANS patients who demonstrate signs of post-infectious autoimmunity and/or neuroinflammation, which are seen in at least 80% of patients. Immunomodulatory treatment is based on disease trajectory and symptom severity. Mild symptoms may only require “tincture of time” and supportive therapies; if persisting, oral corticosteroid bursts and/or nonsteroidal anti-inflammatory drugs are recommended. For moderate-to-severe cases, oral or intravenous corticosteroids may be enough, but intravenous immunoglobulin (IVIG) is often warranted. Severe or chronic symptoms may require prolonged corticosteroid courses or repeated high-dose corticosteroids plus IVIG. Extreme and life-threatening cases may require therapeutic plasma exchange alone or with IVIG, high-dose intravenous corticosteroids, and/or rituximab. 12, 14, 18, 19

Removing Inflammatory Sources

The inflammatory source must be identified and treated promptly to effectively address infection-related inflammation. Recognizable infections often trigger the initial onset and succeeding flares. While streptococcal infection is the most studied inciting infection, many other infections, such as upper respiratory tract infections, Mycoplasma pneumoniae, COVID-19, tick-borne infections, influenza, etc., are known to trigger PANS flares. However, in some cases, life stresses or no apparent inciting factor are the trigger. Even without a documented infection, an antibiotic course targeting streptococcal bacteria is recommended at the time of diagnosis. In severe cases of strep-triggered PANS/PANDAS and in those with recurrent strep infections, extended and/or prophylactic antibiotic courses should be considered. Patients and close contacts should be closely monitored for streptococcal infections and other infections during the initial onset and at signs of exacerbations; if positively diagnosed, treat according to current standard guidelines. 12, 15, 19

Understanding the Full Clinical Picture

Restricted eating in PANS/PANDAS cannot be understood solely by looking at how much or what an individual is eating. Similar outward presentations may arise from very different mechanisms, including contamination fears, obsessive-compulsive symptoms, sensory changes, fear of choking or vomiting, loss of appetite, altered perceptions of food, body-image concerns, or combinations of these symptoms.

Some patients with PANS/PANDAS will also meet diagnostic criteria for ARFID, AN, or another eating disorder. These diagnoses can accurately describe the eating disturbance and help identify the nutritional, medical, and psychotherapeutic support a patient needs. They do not, however, necessarily explain why the eating disturbance developed.

For that reason, the evaluation should consider restricted eating in the context of the patient’s overall clinical presentation. A sudden or newly worsening change in eating accompanied by OCD, anxiety, tics or other motor abnormalities, cognitive or academic changes, regression, sleep disruption, urinary symptoms, emotional changes, or other characteristic PANS/PANDAS symptoms may warrant further medical evaluation.

Regardless of cause, significant food or fluid restriction requires prompt attention. Nutritional rehabilitation and medical stabilization should not be delayed while clinicians determine the underlying diagnosis. Likewise, identifying and treating the eating disturbance should not end the investigation when the broader clinical picture suggests PANS/PANDAS.

Recognizing both sides of this intersection allows care to address the immediate consequences of restricted eating while also identifying and treating the underlying processes that may be contributing to it.

PANS/PANDAS Resources

Sources

  1. Chang K, Frankovich J, Cooperstock M, Cunningham MW, Latimer ME, Murphy TK, Pasternack M, Thienemann M, Williams K, Walter J, Swedo SE; PANS Collaborative Consortium. Clinical evaluation of youth with pediatric acute-onset neuropsychiatric syndrome (PANS): recommendations from the 2013 PANS Consensus Conference. J Child Adolesc Psychopharmacol. 2015;25(1):3-13. doi:10.1089/cap.2014.0084
  2. Swedo SE, Leonard HL, Garvey M, Mittleman B, Allen AJ, Perlmutter S, Lougee L, Dow S, Zamkoff J, Dubbert BK. Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections: clinical description of the first 50 cases. Am J Psychiatry. 1998;155(2):264-271. doi:10.1176/ajp.155.2.264
  3. Swedo SE, Leonard HL, Rapoport JL. The pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) subgroup: separating fact from fiction. Pediatrics. 2004;113(4):907-911. doi:10.1542/peds.113.4.907
  4. Murphy TK, Storch EA, Lewin AB, Edge PJ, Goodman WK. Clinical factors associated with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. J Pediatr. 2012;160(2):314-319. doi:10.1016/j.jpeds.2011.07.012
  5. Murphy TK, Patel PD, McGuire JF, et al. Characterization of the pediatric acute-onset neuropsychiatric syndrome phenotype. J Child Adolesc Psychopharmacol. 2015;25(1):14-25. doi:10.1089/cap.2014.0062
  6. Lougee L, Perlmutter SJ, Nicolson R, Garvey MA, Swedo SE. Psychiatric disorders in first-degree relatives of children with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). J Am Acad Child Adolesc Psychiatry. 2000;39(9):1120-1126. doi:10.1097/00004583-200009000-00011
  7. Swedo SE, Leckman JF, Rose NR. From Research Subgroup to Clinical Syndrome: Modifying the PANDAS Criteria to Describe PANS (Pediatric Acute-onset Neuropsychiatric Syndrome). Pediatr Therapeut. 2012;2:113. doi:10.4172/2161-0665.1000113
  8. Kinderlehrer DA. Anorexia Nervosa Caused by Polymicrobial Tick-Borne Infections: A Case Study. Int Med Case Rep J. 2021;14:279-287. doi:10.2147/IMCRJ.S311516
  9. Toufexis MD, Hommer R, Gerardi DM, et al. Disordered eating and food restrictions in children with PANDAS/PANS. J Child Adolesc Psychopharmacol. 2015;25(1):48-56. doi:10.1089/cap.2014.0063
  10. Kapphahn C. Disordered Eating In Children And Adolescents with PANS. SANE Sweden 2019 PANS Conference.
  11. Pavone P, Ceccarelli M, Marino S, et al. SARS-CoV-2 related paediatric acute-onset neuropsychiatric syndrome. Lancet Child Adolesc Health. 2021;5(6):e19-e21. doi:10.1016/S2352-4642(21)00135-8
  12. Swedo SE, Frankovich J, Murphy TK. Overview of Treatment of Pediatric Acute-Onset Neuropsychiatric Syndrome. J Child Adolesc Psychopharmacol. 2017;27(7):562-565. doi:10.1089/cap.2017.0042
  13. Thienemann M, Murphy T, Leckman J, et al. Clinical Management of Pediatric Acute-Onset Neuropsychiatric Syndrome: Part I-Psychiatric and Behavioral Interventions. J Child Adolesc Psychopharmacol. 2017;27(7):566-573. doi:10.1089/cap.2016.0145
  14. Frankovich J, Swedo S, Murphy T, et al. Clinical Management of Pediatric Acute-Onset Neuropsychiatric Syndrome: Part II-Use of Immunomodulatory Therapies. J Child Adolesc Psychopharmacol. 2017;27(7):574-593. doi:10.1089/cap.2016.0148
  15. Cooperstock MS, Swedo SE, Pasternack MS, Murphy TK. Clinical Management of Pediatric Acute-Onset Neuropsychiatric Syndrome: Part III-Treatment and Prevention of Infections. J Child Adolesc Psychopharmacol. 2017;27(7):594-606. doi:10.1089/cap.2016.0151
  16. Platt MP, Agalliu D, Cutforth T. Hello from the Other Side: How Autoantibodies Circumvent the Blood-Brain Barrier in Autoimmune Encephalitis. Front Immunol. 2017;8:442. doi:10.3389/fimmu.2017.00442
  17. Calaprice D, Tona J, Parker-Athill EC, Murphy TK. A Survey of Pediatric Acute-Onset Neuropsychiatric Syndrome Characteristics and Course. J Child Adolesc Psychopharmacol. 2017;27(7):607-618. doi:10.1089/cap.2016.0105
  18. Kovacevic M, Grant P, Swedo SE. Use of intravenous immunoglobulin in the treatment of twelve youths with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. J Child Adolesc Psychopharmacol. 2015;25(1):65-69. doi:10.1089/cap.2014.0067
  19. PANDAS Physician Network. Evaluation and Treatment Flow Charts.

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Gabriella True

Gabriella True

Published : September 16, 2026
Category : Behavioral Health, Blog, Clinicians, Family Resources, Featured on Homepage

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