Pica in an Adolescent with Autism Spectrum Disorder Responsive to Aripiprazole

To the Editor:

Pica is defined as the persistent eating of nonfood substances (e.g., soap, paper) in a developmentally inappropriate and culturally unacceptable manner. Although its etiology is unclear, intellectual disability, autism, schizophrenia, male gender, nutritional (e.g., iron and zinc) deficiencies, and younger age are among the most common factors associated with pica (Stiegler 2005).

In this report, we describe an adolescent girl with autism spectrum disorder (ASD) who had pica responsive to aripiprazole.

Case Report

A 17-year-old female with a diagnosis of ASD was referred to our outpatient clinic by her parents with complaints of irritability, physical aggression toward her parents, self-injurious behaviors, and coprophagia. According to her mother, she had been eating leaves, soap, detergent, toothpaste, and deodorant since her childhood. She had started eating her feces 6 months before. She had her bowel control when she was 10 years old, and currently did not have any defecation problems, such as constipation or diarrhea. Her mother reported that she engaged in compulsive behaviors including excessive hand washing, changing her clothes frequently (10–15 times a day), and ordering. In her family history, her mother and grandmother both had had a diagnosis of obsessive-compulsive disorder (OCD). Her mother had pica (geophagia) during her childhood. The patient's routine biochemical workup, including complete blood count, ferritin, and iron was within normal limits.

She had been on risperidone 1 mg/day for 15 months for her disruptive behaviors, with partial response. We decided to change risperidone to aripiprazole and increase the dose to 7.5 mg/day over a 3 week-period. In her second visit to the clinic 4 weeks later, her mother reported that her disruptive and compulsive behaviors had decreased, and that her pica resolved completely. During 6 months of treatment with aripiprazole, she did not engage in any pica behavior or experience any side effects.

Discussion

We described an adolescent with pica, which resolved after aripiprazole administration. In the literature, there is only one reported case (a 29-year-old male with ASD) with pica (coprophagia) that improved rapidly with aripiprazole (Pardini et al. 2010). Exacerbation of pica during antidopaminergic (thioridazine) treatment, and improvement with a dopamine agonist (methylphenidate) have been reported (Singh et al. 1994; Hergüner and Hergüner 2010). Aripiprazole is a partial agonist at dopamine D2, and is described as a dopamine system stabilizer. It acts like an antagonist in hyperdopaminergic states, and like an agonist in hypodopaminergic states (Muscatello et al. 2011). We suggest that aripiprazole may have stopped the pica behavior in this reported case by stabilizing dopaminergic transmission.

Several reports described pica as an obsessive compulsive spectrum disorder (OCSD) (Beck and Frohberg 2005; Hergüner et al. 2008). The compulsive behaviors of the patient, and the OCD and pica in her family history support that pica may be related to OCSD. Treatment with selective serotonin reuptake inhibitors (SSRIs) has been shown to reduce pica, which was attributed to their anti-obsessive properties. In our case, both pica and compulsive behaviors improved with aripiprazole, which might be the result of aripiprazole's antianxiety and anti-OCD effects (Muscatello et al. 2011).

This report suggests that aripiprazole may be an alternative in the treatment of pica. However, further studies are needed to investigate the efficacy of aripiprazole in pica.