Delusions of Glass Under Skin: An Unusual Case of Somatic-Type Delusional Disorder Treated with Olanzapine

Introduction
The management of delusional disorder (DD) remains difficult due to poor patient insight and a lack of definitive treatment guidelines. For the somatic subtype specifically, prior studies have shown successful treatment with the first-generation antipsychotics (FGA) pimozide, but these studies did not specify the nature of the delusions. It has been theorized that pimozide effectiveness is due to its unique ability to relieve itching sensations, which are commonly associated with somatic delusions (e.g., delusions of parasitosis). The use of FGAs is not without risk, however, and should be avoided when possible due to the significant side-effect profile. Thus, there is a need for safer alternatives for the treatment of somatic-type DD. This manuscript discusses a case of DD characterized by painful sensations of glass under the skin managed with the second-generation antipsychotic olanzapine.
Case
A 67-year-old female with a past medical history including depression presented to the ED with complaints of glass in her hands and fingernails bilaterally. The patient has been evaluated by several physicians in the past without any evidence of glass being found. She was able factually able to describe that others viewed her complaints as irrational, but she refused to accept this as truth. Cognitive screening testing was normal, and a physical exam showed several areas of excoriation on the hands and arms bilaterally, a removed left thumbnail, and a thin frame (BMI: 18.02). The patient was admitted to the psychiatry service, where organic causes were ruled out (infection, metabolic abnormalities, drug use). The patient received olanzapine 5mg PO nightly treatment with adjunctive psychotherapy and experienced acute psychotic relief after a two-day admission period. She did not endorse any side effects from the medication.
Discussion
To our knowledge, there haven’t been prior studies exploring treatment efficacy in somatic-type DD subdivided by the nature of false bodily sensation. Despite this limitation, it was found that most cases of somatic-type DD characterized by foreign bodies under the skin were treated with pimozide. Although this drug appears to be a reasonable option for the more common presentation involving false pruritis, it might not be recommended for rare presentations that don’t involve itchiness due to the high risk of adverse symptoms. Accordingly, clinicians should consider the nature of the delusions along with the unique side effect profile of the pharmacological therapy as any harm might outweigh the potential benefit. This was highlighted in the current presentation as clinicians determined olanzapine to be the most appropriate treatment despite no similar cases of DD described in the literature. Furthermore, this case exemplified the utility of second-generation antipsychotics in the treatment of somatic-type DD.
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