Letter to the Editor: Skin-Testing for Clones—Pediatric Obsessive Compulsive Disorder with Misidentification Syndrome

To the Editor:

The phenotypic manifestations of obsessive-compulsive disorder (OCD) are consistent across ages, although in pediatric OCD, symptoms are influenced by age-related factors (e.g., focus on fantasy, less stringent reliance on reality testing, higher tolerance to the irrationality or implausibility of obsessions). In this respect, the emergence of bizarre and/or illogical obsession contents (e.g., transformation obsession: Volz and Heyman 2007) brings to the clinical foreground the importance of timely differential diagnosis with putative early onset psychosis and related risk antecedents such as attenuated psychotic symptoms (Raballo et al. 2020). Since the syndromic presentations of pediatric OCD can be very nuanced and accompanied by stringent clinical dilemmas, we wish to report a case with contextual misidentification features.

Siegfried (pseudonym) is a 11-year-old boy, without prior psychiatric illness and psychiatric illness in parents, who was referred for increasing social anxiety in the transition to middle school. The assessment revealed the presence of an OCD, confirmed in its severity by the Children's Yale-Brown Obsessive Compulsive Scale (score 31). The clinical assessment, including developmental anamnesis and the Kiddie Schedule for Affective Disorders and Schizophrenia Present and Lifetime Version (KSADS-PL), excluded the presence of additional current schizotypal or autistic symptoms.

He reported the obsessive fear that his parents could have been replaced by clones; although he acknowledged the irrational and illogical nature of such painfully intrusive thought, he nonetheless felt obliged to enact a compulsive misidentification ritual every evening before falling asleep. The ritual specifically consisted in a scrupulous check of idiosyncratic skin signs on the body of his parents. Such daily “skin-test” (i.e., concretely inspecting a certain tattoo on his father and some specific skin-moles on his mother) allowed him to confirm the authenticity of his parents (i.e., their identity). Establishing a therapeutic alliance with the boy and the family and at the same time assisting the parents in reducing their participation to the presleep ritual led to its progressive fading in some weeks, without pharmacotherapy. The symptomatic behavioral remission was confirmed at the 6-month follow-up.

Delusional misidentification syndromes represent a superordinate cluster of psychopathological conditions in which an individual misidentifies persons, places, objects, or events; the most common form is Capgras syndrome, which characterized by the nonrecognition of familiar persons, who are believed to have been replaced by doubles, clones, or imposters. Misidentifications syndromes are rarely reported in nonpsychotic conditions, with only few anecdotal case reports in OCD (Stein et al. 1988; Melca et al. 2013), as the case of a 33-year-old man reporting intrusive horrific images of someone assaulting his wife and children, associated with an apotropaic protective misidentification ritual (in which he mentally substituted the face of the possible assailant with faces of three differently previously known individuals) (Sevincok et al. 2018).

To our knowledge, we report, for the first time, misidentification syndrome (i.e., parents replaced by clone) in a pediatric patient with OCD, which triggered compulsive checking rituals (i.e., verifying idiosyncratic bodily signs to validate his parents' identity).