Delusional infestation may be caused by recreational drug usage in some patients, but they may not disclose their habit

State-of-the-Art Review: Evaluation and Management of Delusional Infestation

Delusional infestation is a condition encountered frequently by healthcare professionals across a variety of specialties in which patients have a fixed, false belief that they are infested with living creatures, such as bugs, parasites, worms, or mites, or nonliving objects, such as fibers. Delusional infestation can be debilitating for patients, who not only present with intense psychological distress and physical discomfort but are also at risk of developing numerous dermatological and psychiatric complications. This condition poses unique diagnostic challenges, as these symptoms can occur secondary to many metabolic or infectious causes, as well as unique treatment challenges, with patients frequently refusing psychiatric care and consequently seeking evaluation by other healthcare professionals. In this review, we aim to use existing literature to provide clinicians in infectious diseases or other specialties with sufficient clinical context and treatment guidance for the appropriate management of delusional infestation.

Mucocutaneous Manifestations of Recreational Drug Use

Recreational drug use is increasingly common in the dermatology patient population and is often associated with both general and specific mucocutaneous manifestations. Signs of substance use disorder may include changes to general appearance, skin, and mucosal findings associated with particular routes of drug administration (injection, insufflation, or inhalation) or findings specific to a particular drug. In this review article, we provide an overview of the mucocutaneous manifestations of illicit drug use including cocaine, methamphetamine, heroin, hallucinogens, marijuana, and common adulterants to facilitate the identification and improved care of these patients with the goal being to connect this patient population with appropriate resources for treatment.

Delusional infestation: a retrospective cohort study of 49 patients over a 6-year period

Delusional infestation (DI) is the fixed false belief of pathogenic infestation of the skin or body despite no supporting medical evidence. It is a relatively rare condition with a reported prevalence of 1.48 per million people. Successful treatment can be challenging as patients are often reluctant to accept referral or involvement of psychiatric services. We report a retrospective cohort study of 49 consecutive patients with a diagnosis of DI, assessed in a regional psychodermatology service over a 6-year period. Low-dose antipsychotics (risperidone or olanzapine) were prescribed in 44 patients. We use our data to explore possible reasons why DI can be challenging to treat. Response to treatment and engagement with services is multifactorial. Our study emphasizes the importance of early assessment and supports the expansion of psychodermatology services in the UK.

“Doctor, You Must Examine My Creature Collection!”: A Case Report of Delusional Infestation

Delusional infestation--either secondary when attributed to a medical condition (including a bon-a-fide parasite infestation) or a pharmacologic agent (prescribed or illicit) or primary when secondary etiologies have been excluded--is a psychosis in which, for at least one month duration, the patient not only has a delusion that an animate organism or an inanimate pathogen has infested them, but also has abnormal tactile sensation (such as pruritus) of their skin caused by the etiology of their delusion. In patients over the age of 50 years, a delusional infestation is three times more common in women than men; however, delusional infestation in younger patients is often secondary, associated with illicit drug exposure, and equally common in women and men. Primary skin lesions are typically absent in delusional infestation patients; however, secondary skin lesions--resulting from the patient’s efforts to remove the parasite from their skin--can be observed, such as excoriations, prurigo nodules, scars, and ulcers. Delusional infestation patients typically strive to convince the person evaluating them that their infestation is valid and many of these individuals do this by collecting the parasites in a container. Presentation of the pathogen-filled containers is a pathognomonic feature of delusional infestation that has been referred to as either a positive creature collection sign, match box sign, parasite preservation sign, pillbox sign, or specimen sign. Morgellons disease--in which the pathogen being extruded from the skin is a fiber--has several features (including an excellent response to treatment with antipsychotic agents) in common with delusional infestation; therefore, most investigators consider Morgellons disease to be a variant of delusional infestation. Delusional infestation can be associated with numerous diseases, including comorbid psychiatric conditions. Indeed, up to 15 percent of delusional infestation patients have one (folie a deux) or more individuals with similar symptoms. A man with delusional infestation is described who had a positive creature collection sign, a fixed belief that his symptoms were caused by the infesting organism, and refusal to accept that he had a psychiatric disorder. He insisted that the evaluating dermatologist examine the pathogens in the clear plastic container he brought with him to his appointment. He was convinced that the pruritus of his scalp, eyebrows, and eyelashes was associated with a non-existent lice infestation. Secondary delusional infestation was excluded and his concurrent mild seborrheic dermatitis was treated topically; however, his itching did not resolve. He eventually agreed to seek treatment with a psychiatrist. The management of delusional infestation is based on its etiology; resolving the underlying medical condition or discontinuing the causative pharmacologic agent is the treatment approach for secondary delusional infestation, whereas low-dose antipsychotic agents are the intervention of choice for treating primary delusional infestation.

Historical and clinical considerations on Ekbom's syndrome

Ekbom's syndrome represents a relatively uncommon neuropsychiatric condition characterized by the recurrent and bizarre fixed delusional belief to be infested by small organisms or even unanimated materials ('Morgellons disease'), without any objective evidence of infestation/parasitosis. The condition, mainly diagnosed in a nonpsychiatric setting, is supposed to be largely underestimated and, hence, undermanaged. The present comprehensive review aims at investigating Ekbom's syndrome, from a historical, epidemiological, clinical and therapeutic perspective, by providing diagnostic-treatment strategies in managing this condition in routine psychiatric clinical settings. The prototypical patient is a middle-aged woman (or a younger subject in those cases in which substance and/or alcohol abuse is implicated), often single, divorced or widowed (loneliness component and social withdrawal), who has already consulted several specialists due to skin lesions associated with a firm and delusional belief to be infested. The identification and diagnosis are challenging due to poor patient's insight, poor knowledge and collaboration between specialists and differential diagnoses to be considered before asking for a psychiatric referral. Management and treatment strategies mainly derive from isolated case reports or observational studies with a small sample size. Further randomized clinical trials should be performed to evaluate the efficacy of newer antipsychotic drugs, including long-acting injectable formulations.

Current Understanding and Approach to Delusional Infestation

Delusional infestation is a psychiatric condition defined by a fixed belief of infestation despite contrary evidence. Diagnosis includes exclusion of organic etiologies. Treatment with antipsychotics is effective and safe in the majority of patients. Patients are characteristically reluctant to pursue psychiatric evaluation and may resist discussing their disease in psychiatric terms. Strategies to strengthen the provider-patient therapeutic alliance facilitate communication around appropriate treatment. Without antipsychotic medications, patients can become heavy utilizers of care and practice self-destructive behaviors in attempts to clear their perceived infestation.

Association Between Delusions of Infestation and Prescribed Narcotic and Stimulant Use

OBJECTIVE

Patients diagnosed with delusions of infestation (DOI) at a psychodermatology clinic appeared to have a higher incidence of being prescribed narcotic or stimulant medications compared with the general dermatologic clinic population with chronic pruritic conditions. A retrospective study was conducted examining the correlation between patients with DOI and prescribed psychoactive medications.

METHODS

Ninety-two patients with a diagnosis of DOI, seen at our University Psychodermatology Clinic, served as the study population. The comparison group (N=354) included dermatology patients seen at a dermatology clinic by the same dermatologist for itching, including adults seen for chronic pruritic conditions and contact dermatitis. For both groups, the reported use of any psychoactive prescription medications was noted.

RESULTS

Patients with DOI were significantly more likely than other dermatology patients to receive prescriptions for narcotics [adjusted odds ratio (OR)=2.19; confidence interval (CI)=1.21-3.99) and stimulants (OR=5.44; CI=2.37-12.52). Patients with DOI were also more likely to be female (OR=2.49; CI=1.47-4.22) than patients who did not have such delusions.

DISCUSSION

Few data are available concerning the etiology and management of DOI. Findings from this study indicated an association between the diagnosis of DOI and the prescribing of narcotics and stimulants, even when sex and age were taken into account. This information may be used to assist with the diagnosis of patients presenting with DOI and possible treatment options. It will be important to determine if these medications are a cause of the condition, or are merely correlated with other medical conditions.

Management of the psychological comorbidities of dermatological conditions: practitioners' guidelines

Dermatological disease can be devastating for patients, and although dermatologists are focused on remedying the cutaneous manifestations of these conditions, it is easy to miss the psychological suffering lurking below. Studies reveal that psychiatric comorbidity in dermatology is highly prevalent. Undetected psychopathology can greatly decrease a patient's quality of life and even contribute significantly to the clinical severity of their skin disease. For these reasons, it is vital that practitioners learn to detect psychological distress when it is present, and it is equally essential that they understand the treatment options available for effective intervention. Without training in psychiatric diagnosis and psychopharmacology, dermatologists can easily feel overwhelmed or out of their comfort zone when faced with the need to manage such conditions, but with the negative stigma associated with psychiatric disease in general, a psychiatric referral is often refused by patients, and the dermatologist is thus left with the responsibility. Uncertainty abounds in such situations, but this review seeks to alleviate the discomfort with psychodermatological disease and share practical and impactful recommendations to assist in diagnosis and treatment. In a busy dermatology clinic, the key is effective and efficient screening, combined with a repertoire of pharmacological and non-pharmacological treatment options that can be dispersed through an algorithmic approach according to the specific findings of that screening. By implementing these recommendations into practice, dermatologists may begin to gain comfort with the management of psychocutaneous disease and, as a specialty, may expand to fill a hole in patient care that is truly significant for patients, their families, and our communities as a whole.