**3. Differential diagnosis**

Before discussing various disorders that need to be differentiated from OCD, it is important to recognize that within normal development there are rituals that would not be considered dysfunctional.

#### **3.1. Normal development**

Young children often seek out and find comfort in routines, for example, reading the same bedtime story every night, playing with the same toys each time at the library, or requesting the same afternoon snack every day. While these behaviors may appear ritualistic on the surface, they would not be classified as compulsions if they do not cause significant impairment or are excessively time-consuming; additionally, interruption of these rituals typically would not cause severe distress in the child [17]. Generally, children will gradually reduce their reliance and preference for these rituals as they age with little issue. These routines are to be distinguished from the presence of obsessions and compulsions, which often involve repetitive behavior, however, typically at a higher frequency and intensity and with the addition of high anxiety and distress when rituals are interrupted. Notably, children do not customarily just "grow out" of OCD so it is important that parents address the issue and provide appropriate treatment rather than minimize the impact of the symptoms or accommodate as a short-term fix [18, 19].

**3.3. PANDAS/PANS**

"Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections" (PANDAS) refers to a particular subtype of pediatric OCD with abrupt onset, episodic course of illness, and a number of distinctive features [23, 24]. The original diagnostic criteria for PANDAS included (1) the presence of OCD and/or a tic disorder, (2) onset of these symptoms prior to puberty, (3) abrupt onset of symptoms, and (4) association with autoimmune infection group A streptococcus (GAS) [24]. The autoimmune response in PANDAS contributes to inflammation of the basal ganglia and subsequent dysfunction of the brain structure [24]. Researchers began investigating PANDAS when they identified a subset of pediatric individuals who had an unusual course of OCD symptoms: a sudden dramatic onset followed by a gradual reduction over several months [23, 24]. They noted similarities to individuals with Sydenham's chorea (a type of rheumatic fever) and, upon further investigation, noted that

Manifestation and Treatment of OCD and Spectrum Disorders within a Pediatric Population

http://dx.doi.org/10.5772/intechopen.79344

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numerous patients with chorea also had obsessive compulsive symptoms as well.

varicella, mycoplasma infections, and chronic Lyme disease [26].

association to GAS or other infectious triggers.

PANDAS symptoms are documented as early as age 3 and intensification of symptoms can occur within mere days [24]. An investigation of 50 clinical case studies identified average age of onset for PANDAS with obsessive compulsive symptoms at 7.4 and with tic symptoms at 6.3 [24]. To be classified as PANDAS, the symptoms must be temporally related to GAS infection such as a positive throat culture or elevated anti-GAS antibody titers. Patients also often exhibit neurological irregularities such as motor hyperactivity and tics though these may wax and wane during periods of remission. Other symptoms associated with PANDAS include impulsivity, distractibility, emotional lability, separation anxiety, age-inappropriate behavior, bedwetting, and handwriting disabilities [24, 25]. Of note, PANDAS-like symptoms have been exhibited in response to other bacterial and viral infections including influenza,

Recently, researchers noted potential challenges with the original diagnostic criteria of PANDAS (such as difficulty establishing temporal association with GAS infection as well as difficulty distinguishing between PANDAS and non-PANDAS cases). Thus, researchers have reviewed the original diagnostic criteria and available data to establish PANS: pediatric acute-onset neuropsychiatric syndrome [26]. PANDAS is now considered under the rubric of PANS. Diagnostic criteria for PANS include (1) abrupt, dramatic onset of obsessive compulsive disorder, (2) severely restricted food intake, (3) concurrent presence of additional neuropsychiatric symptoms from at least two of the following seven categories: anxiety; emotional lability and/or depression; irritability or aggression; behavioral regression; reduced school performance; motor abnormalities; somatic symptoms including sleep disturbance, enuresis, or urinary frequency, and (4) symptoms are not better explained by a neurological or medical disorder [26]. PANS is conceptualized as a broader clinical entity that can be related to a preceding infection; however, it also refers to acute-onset symptoms without apparent immune disturbance [26]. If a child does exhibit the clinical criteria of PANS, the possibility of PANDAS should be explored and appropriate laboratory studies conducted to determine any

Treatment for PANS includes standard OCD treatments including exposure and response prevention as well as psychotropic medications (selective serotonin reuptake inhibitors,

#### **3.2. When do rituals become dysfunctional?**

Obsessive compulsive disorder involves intrusive and anxiety-provoking thoughts, images, and/or impulses (obsessions) and repetitive mental or behavioral actions intended to reduce anxiety and prevent feared negative consequences (compulsions), which cause distress, are time consuming, and cause functional impairment [20]. The content of obsessions and compulsions often varies such that OCD can appear quite heterogeneous across cases: one child may repeatedly wash their hands throughout the day in an effort to prevent life-threatening illnesses, while another child repeats certain phrases to ensure "bad" thoughts do not lead to the occurrence of "bad" events. Additionally, two children may wash hands repeatedly and display similar compulsions for entirely different obsessional themes (for example, one child may fear germs, whereas another child seeks a "just right" feeling). The Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) is considered the gold standard for assessment of OCD and includes a clinician-rated checklist of common obsessions and compulsions, which allows for specificity and clarity of symptoms [21].

Diagnosing OCD is complicated as it manifests quite differently across cases and symptoms can appear similar to other disorders [22]. Children and adolescents may attempt to hide their symptoms due to shame or embarrassment about having "bad" or irrational thoughts or unusual behaviors, which may cause parents or clinicians to miss or overlook dysfunction [17]. As children are still developing with regard to verbal communication abilities, they may not articulate clear obsessions. Similarly, mental rituals may go undetected. Also, as discussed above, children with OCD may have comorbid conditions, which can lead to challenges in distinguishing symptoms between diagnoses. Symptoms of different conditions can look quite similar in presentation; that is, does a child who repeatedly asks for reassurance and checks for physical ailments related to fear of throwing up have a separate phobia or is the fear of vomiting considered another manifestation of OCD? Certain tics can also manifest quite similarly to behavioral compulsions related to symmetry or "just right" feeling. Differential diagnosis must be carefully conducted particularly in situations where treatment recommendations would differ. Below are some disorders that need to be considered in differential diagnosis.
