Delusional Dermatoses Tamed by ‘Therapeutic Alliance’

ORLANDO, Fla. — Whether primary or secondary, delusional infestations (DI), a condition known by many names, can be effectively treated with a step-by-step process based on forming a therapeutic alliance, according to Jenny Murase, MD, an associate clinical professor of dermatology at the University of California San Francisco. 

Murase, the senior author of a method that has been used for more than 15 years and was described in a 2013 review article, updated her strategy in a symposium devoted to psychocutaneous disease. Murase laid out her multistep approach March 8 at the 2025 annual meeting of the American Academy of Dermatology. 

The approach involves four phases with a focus on curing symptoms rather than convincing patients that the symptoms are delusional, which is typically counterproductive, Murase explained. 

She did not deny that these patients are challenging, and she said the four-phase approach requires preparation, adherence to the underlying strategy, and a multifaceted diagnostic workup. However, she also offered several tips on how to limit the amount of time this process would otherwise consume.

The first three phases are essential to forming the therapeutic alliance required for treatment success, and as such, they are more critical than the final treatment phase. 

In the first phase, clinicians start with the premise that the ultimate goal is to relieve symptoms, not to make a diagnosis. Patients must be allowed adequate time to describe their clinical complaint in detail. Because such conversations typically do not fit into the schedule of most clinical dermatologists, she suggested using their staffs.

A medical assistant taking a detailed history with notes should be attentive to the patient’s concerns in order to begin building the rapport needed to create a therapeutic alliance. When Murase first sees patients, she hears their complaints before reassuring them that she has encountered these symptoms and presentation before and has treated them successfully. 

Patients with DI whose complaints have been doubted before are commonly defiant during the initial visit. Murase suggested clinicians should prepare for this scenario and maintain an empathic and positive approach while patients recount their history. By accepting that the symptom burden patients describe is credible and significant, clinicians can boost their own motivation to address the problem, she said. 

The second phase is also an attempt to further a therapeutic alliance. A positive attitude supported by body language, such as sitting side by side rather than face to face, can help. Perhaps most importantly, Murase said clinicians should do their best to redirect attention from reaching a diagnosis to addressing the symptoms collaboratively in order to settle on a treatment.

“Ask the patient whether it is more important to find the bug or to improve the condition,” said Murase, warning that most patients are focused at first on validating the source of their symptoms rather than the symptoms themselves. By deflecting attention from a diagnosis to a cure, she is able to once again reassure patients about achieving a successful outcome. 

The third phase involves a thorough physical examination with laboratory testing. Murase often delegates this to a staff member who is expected to take the time needed to meet the goal of “communicating respect for the patients’ complaints and well-being.” She also said that when skin conditions such as contact dermatitis or secondary infection are identified, they can be incorporated into the treatment plan and might contribute to the sense of a therapeutic alliance.

In the third phase, a biopsy can be useful. Murase suggested that patients be consulted about where the biopsy is performed, noting that a biopsy without a target could be considered controversial — but it does have a therapeutic role. As part of the process to establish a therapeutic alliance, a biopsy can be a useful data point for patients who are concerned that not all diagnostic steps have been taken. She often uses a negative biopsy as a tool to refocus patients on symptoms rather than a definitive diagnosis.

“Patients can be reminded that physicians treat patients all the time when the exact etiology is unknown,” said Murase, indicating that a thorough examination is part of the strategy to convince patients that a rational approach is being taken.

Although patients often can accept that they have an uncommon disease that is not readily identified, the therapeutic alliance is readily upset by any suspicions that the clinician considers the symptoms delusional. In the age of patient portals, charting is a threat. Murase recommended replacing terms like “psychosis” or “delusions” with alternatives such as “formication,” which refers to the tactile sensation of crawling bugs, or “cutaneous dysesthesia.”

“Use direct quotes from the patient describing their delusion [in the chart],” she advised. She said other clinicians subsequently reading the chart will recognize delusional statements for what they are.

For treatment, a variety of antipsychotic therapies, such as haloperidol, can be effective for these symptoms, but Murase typically starts with a low dose (0.5 mg) of pimozide, which is indicated for Tourette syndrome. By doing so, the indication is unlikely to alert patients to the fact that their treatment is a psychiatric medication.

If pimozide does not provide adequate relief, other therapies can be considered to keep patients focused on controlling symptoms and improving quality of life. However, an initial therapy that is not immediately recognized as a psychiatric drug provides a basis for working toward symptom control, Murase noted. 

This basic approach resonated with John Y. Koo, MD, director of the Psoriasis and Skin Treatment Center at UCSF. Board certified in both dermatology and psychiatry, Koo was the senior author of a recently published study showing that pimozide has antibacterial and antiparasitic effects.

Like Murase, Koo has prescribed this drug primarily for its psychiatric effects but said he now has evidence to tell skeptical patients with DI that it also has antiparasitic properties.

Speaking in the same symposium as Murase, Koo added that dermatologists can — and should — be prescribing psychiatric medications when indicated for patients with comorbid depression or other conditions secondary to their dermatologic diseases.

“Only dermatologists ask themselves whether they should be prescribing these drugs,” he said, noting that the majority of drugs for psychiatric diseases are prescribed by non-psychiatrists. He said that when dermatology patients will benefit from psychiatric drugs, “it is both legal and ethical” to prescribe them.

Murase has financial relationships with AbbVie, Amgen, Arcutis, Bristol-Myers Squibb, Dermavant, Eli Lilly, Galderma, Regeneron, Sanofi, and UCB. Koo reports financial relationships with AbbVie, Apogee, Arcutis, Bristol-Myers Squibb, Eli Lilly, Galderma, Janssen, Leo, Pfizer, Regeneron, Sanofi, Sun, and UCB.