Delusional Parasitosis (DP): When Pest Control Isn’t the Answer
Delusional Parasitosis (DP) is a rare but serious psychological condition in which a person has a persistent, false belief that they are infested with insects, mites, or other parasites, despite the absence of any evidence. The condition may also be referred to as Delusional Infestation, Delusory Parasitosis, or Ekbom Syndrome.
Individuals with DP may believe that they, their belongings, or even their pets are infested.
Symptoms and the Cycle of Delusion
People suffering from DP often experience intense itching, scratching, and skin picking. These behaviors can result in:
· Open wounds
· Bleeding
· Scabbing
· Secondary skin infections
Unfortunately, these self-inflicted skin injuries often reinforce the individual’s belief that insects are present, creating a cycle that progressively worsens both their physical and mental health.
A Multidisciplinary Approach
Successfully helping someone with Delusional Parasitosis requires collaboration between several professionals, including:
· Pest management professionals
· Primary care physicians
· Dermatologists
· Mental health professionals
· Entomologists
Each plays an important role in identifying the true cause of the problem while ensuring the individual receives appropriate medical care.
The Importance of Empathy and Integrity
Individuals with DP are genuinely convinced they are being bitten by insects that are not present. Because of this belief, many repeatedly contact multiple pest control companies seeking relief.
A common industry problem occurs when companies perform pesticide treatments without confirming that an infestation actually exists. While this may temporarily satisfy the customer’s request, unnecessary treatments rarely solve the problem. When the treatments fail, the individual often hires another company, further reinforcing the delusion and potentially exposing themselves to excessive pesticide use.
Pest management professionals have an ethical responsibility to avoid unnecessary treatments and instead provide honest, evidence-based recommendations.
A Field Experience
After studying psychology, I was introduced to Delusional Parasitosis and its impact on the pest control industry. My first experience with a DP client reinforced the importance of listening before taking action.
The customer had already hired several pest control companies without finding a solution. Rather than immediately applying pesticides, I conducted a thorough inspection of the home.
The inspection revealed no insects—only household dust. To ensure nothing had been missed, I placed monitoring devices and scheduled a follow-up visit.
When I returned, the monitors confirmed there was still no evidence of insect activity.
Despite this, the customer pleaded for another pesticide treatment. Based on my training and the lack of evidence, I declined to spray.
Instead, I explained how bed bugs and other biting insects behave, discussed what evidence would normally be present during an infestation, and gently encouraged the customer to seek medical advice.
Throughout the visit, the customer repeatedly attempted to show me marks she believed were insect bites. While these situations can be uncomfortable, it is important to remain respectful, maintain professional boundaries, and focus on objective findings.
I charged only for the inspection and my time. Later, I learned that the customer had been diagnosed with a medical condition rather than a pest infestation.
This experience confirmed that integrity sometimes means choosing not to perform a treatment.
Lessons for Pest Management Professionals
Unfortunately, some pest control companies continue to perform treatments without confirming pest activity. This often stems from insufficient training or a lack of understanding of Delusional Parasitosis.
When dealing with potential DP cases, technicians should prioritize empathy, education, and professionalism over selling a treatment.
Warning Signs
Be alert for customers who:
· Have hired multiple pest control companies without success.
· Report ongoing bites despite repeated treatments.
· Cannot provide evidence of insects during inspections.
· Insist on pesticide applications even when no pest activity is found.
Best Practices
When encountering a potential DP case:
· Listen carefully to the customer’s concerns and history.
· Conduct a thorough inspection of the property.
· Look for objective evidence before recommending treatment.
· Educate the customer about bed bugs and other biting insects.
· Explain your findings clearly and honestly.
· Encourage medical evaluation when appropriate.
· Maintain professional boundaries and avoid examining or discussing skin lesions in detail.
· Never apply pesticides without evidence of an infestation.
Professional Integrity
Choosing not to perform a pesticide treatment is not a failure or a loss of business. It demonstrates professionalism, ethical decision-making, and a commitment to protecting both the customer and the reputation of the pest management industry.
In cases involving Delusional Parasitosis, empathy, honesty, and integrity are often the most valuable services a pest management professional can provide.
Key Takeaway
When there is no objective evidence of pest activity, the most professional response is not another pesticide treatment—it is a thorough inspection, honest communication, and an appropriate referral when necessary.
Geraldine O’Sullivan is a Service Manager for Orkin Canada, based in Edmonton. She has been in the industry for 14 years, starting as a Technician and moving on to leadership as a Service Manager. A big focus in her career has been safety – she served on Health and Safety committees for many years. Geraldine enjoys training and guiding technicians for success. She has a passion to bring quality educational opportunities to the members and to advocate for positive changes to the industry. Geraldine is currently the President-elect for APMA and will begin her term in the spring of 2027.