Appeal type: Medical Necessity
Decision: Upheld

Nature of Statutory Criteria/Case Summary: An enrollee has requested colonoscopy for treatment of the enrollee, who has been diagnosed with delusional parasitosis.  Findings: The physician reviewer found that the records fail to demonstrate the medical necessity of the requested services.  Delusional parasitosis is a rare disorder in which patients have a delusion that they are infected by parasites or other living organisms. Patients commonly present for general medical or dermatologic care (rather than psychiatric care) with a fixed, false belief of infestation. They typically describe pruritus and frequently have excoriations from scratching. They often have a history of dermatologic complaints.  In this case, the patient has presented several times with complaints of abdominal pain, constipation and witnessed worms infecting her stool. With regards to the work-up of an adult with abdominal pain, laboratory studies are determined by the history and physical and will vary depending on the suspected etiology.  The imaging modality chosen will depend on suspected etiologies. Imaging modalities that may be used to evaluate abdominal pain include ultrasound, computed tomography scan, magnetic resonance imaging (including magnetic resonance cholangiopancreatography), endoscopy, and endoscopic retrograde cholangiopancreatography.  In this case, the patient has had an extensive work-up including upper and lower gastrointestinal endoscopy with biopsies, stool studies for parasites, and laboratory studies including comprehensive metabolic panel and complete blood count.  All of these studies have been negative.  The patient has been diagnosed with delusional parasitosis with anxiety and depression.  The patient has had a normal colonoscopy in the preceding two years without any new bowel complaints that would warrant repeat examination.  Multiple sets of stool studies have been negative.  Therefore, the repeated comprehensive parasitic test of stools is not medically necessary.  The skin lesion she complains of is consistent with dermatitis, which does not require a skin biopsy.  As the patient has been diagnosed with delusional parasitosis and has previously been treated with ivermectin without resolution of her symptoms, there is no indication ivermectin would be beneficial in this case.  Therefore, the requested colonoscopy for the purpose of obtaining a tissue biopsy sample of the lower colon, comprehensive parasitic test of stools, tissue biopsies of skin on right arm, and ivermectin 100 mg, given intravenously for three consecutive days are not medically indicated for the treatment of this patient.Final Result: The reviewer determined that the requested services and medication are not medically necessary for treatment of the patients medical condition. Therefore, the Health Plans denial should be upheld.Credentials/Qualifications: The reviewer is board certified in internal medicine and is actively practicing. The reviewer is an expert in the treatment of the enrollees medical condition and knowledgeable about the proposed treatment through recent or current actual clinical experience treating those with the same or a similar medical condition.