Cocaine abuse: dermatologic manifestations and therapeutic approaches

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.

“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.

Drug-induced Delusional Infestation

It is considered that certain drugs might induce delusional infestation, yet, to date, no studies have been performed to identify the pharmacodynamics associated with these treatments. The aim of this review is to summarize current available knowledge of drug-induced delusional infestation. A literature search was performed for primary studies on suspected drugs reported to induce delusional infestation. Included articles were evaluated systematically using the Naranjo criteria. In addition, drug mechanisms of action were compared. The final selection included 31 studies, in which a total of 26 classes of drugs were identified. Anti-Parkinson drugs were most frequently associated with delusional infestation, followed by antidepressants, antiepileptics, antibiotics, prescription stimulants, and a few other drug groups. The current available literature suggests that the onset of delusional infestation is initiated by drug-induced alterations in neurotransmitter levels, predominantly dopamine, in the central nervous system.

The effects of alcohol and illicit drug use on the skin

Early identification of cutaneous manifestations of alcohol and illicit drug use can aid in the diagnosis and management of these uses, as well as their sequelae. In addition, the effects of alcohol and illicit drug use on the skin can result in significant morbidity. Alcohol misuse can present with jaundice, pruritus, pigmentary alterations, urticaria, hair and nail changes, and oral changes. It is also a risk factor for skin cancer and infections. Vascular disturbances associated with alcohol misuse include telangiectasias, palmar erythema, caput medusae, and flushing. Diseases related to alcohol misuse include nutritional deficiencies, porphyria cutanea tarda, psoriasis, seborrheic dermatitis, nummular dermatitis, and rosacea. Other conditions seen in alcohol misuse include Dupuytren contracture, Peyronie disease, and pancreatitis. Dermatologists should also be aware of hepatotoxic medications that are commonly prescribed for skin diseases so as to avoid initiating hepatoxicity in patients who use alcohol. Illicit drug use can manifest with cutaneous fibrosis, scarring, granulomas, ulceration, pruritus, infections, cocaine-levamisole-induced vasculitis, tooth decay, and oral disease. By recognizing the cutaneous stigmata of alcohol and illicit drug use, dermatologists can aid in the identification and treatment of patients suffering from these addictions.

Holistic dermatology: An evidence-based review of modifiable lifestyle factor associations with dermatologic disorders

BACKGROUND

Holistic dermatology focuses on treating the human body as a whole and implementing lifestyle changes to enhance the treatment and prognosis of skin disease. Understanding the interplay between modifiable lifestyle factors and patients' dermatologic health will help physicians better inform patients on self-care methods to mitigate the burden of their skin disease(s).

OBJECTIVE

To review the current scientific literature on the relationship between modifiable lifestyle factors and the dermatologic outcome of skin disorders.

METHODS

A systematic literature search on PubMed, Cochrane, and Web of Science was conducted to identify research articles examining the relationship between dermatology and 6 major categories of modifiable lifestyle factors: diet, sleep, exercise, stress, alcohol, and smoking.

RESULTS

A substantial amount of evidence supports the relationship between modifiable lifestyle factors and dermatologic outcomes. There were the most studies on diet, stress, alcohol, and smoking, but all lifestyle factors were supported by some degree of scientific evidence.

CONCLUSION

All modifiable lifestyle factors explored in this review play a critical role in modulating the onset and progression of skin disease. We anticipate more research studies in the future and an increasing integration of holistic dermatology into patient care.

Pitfalls and Pearls in Delusional Parasitosis

Delusional parasitosis is an uncommon psychiatric disorder that manifests as having parasitic delusions. Due to its rarity, delusional parasitosis is a challenging and costly diagnosis of exclusion and proves difficult to manage for many providers. Although this syndrome is frequently discussed in psychiatric and dermatology reports, it is not commonly described in emergency medicine (EM) literature. As a result, best practices for workup and treatment remain unclear from an EM perspective. Patients typically return multiple times for medical evaluation and exhaust numerous resources. In this case report we review the appropriate steps for initial evaluation of patients with suspected delusional parasitosis, differential diagnoses, and increase awareness for prudent treatment strategies.

A nanoporous gold-based electrochemical aptasensor for sensitive detection of cocaine

The increasing application of aptamers in bioassays has triggered a lot of research interest for development of highly sensitive and selective sensing platforms. Herein, we report on the design of a sensitive cocaine biosensor by immobilizing the 5′-disulfide-functionalized end of an aptamer sequence on a nanoporous gold (NPG) electrode followed by the conjugation of its 3′-amino-functionalized end to 2,5-dihydroxybenzoic acid (DHBA) as the redox probe. In the presence of cocaine, the aptamer undergoes a conformational change from an open unfolded state to a closed conformation, which reduces the distance between DHBA and the electrode surface, resulting in the enhanced electron-transfer efficiency. Using square wave voltammetric method and under the optimal conditions, the cocaine aptasensor presented two linear responses in the concentration ranges between 0.05–1 and 1–35 μM, with an excellent detection limit of 21 nM. The proposed aptasensor provides a simple and low-cost method for cocaine detection with good reproducibility and accuracy. Furthermore, it could be regarded as a general model to investigate the unique function of aptamer-functionalized nanostructured electrodes to stablish highly advanced electrochemical biosensors for various target analytes of diagnostic importance.

The increasing application of aptamers in bioassays has triggered a lot of research interest for development of highly sensitive and selective sensing platforms.

Recorded atypical hallucinations in psychotic and affective disorders and associations with non-benzodiazepine hypnotic use: the South London and Maudsley Case Register

OBJECTIVES

Hallucinations are present in many conditions, notably psychosis. Although under-researched, atypical hallucinations, such as tactile, olfactory and gustatory (TOGHs), may arise secondary to hypnotic drug use, particularly non-benzodiazepine hypnotics ('Z drugs'). This retrospective case-control study investigated the frequency of TOGHs and their associations with prior Z drug use in a large mental healthcare database.

METHODS

TOGHs were ascertained in 2014 using a bespoke natural language processing algorithm and were analysed against covariates (including use of Z drugs, demographic factors, diagnosis, disorder severity and other psychotropic medications) ascertained prior to 2014.

RESULTS

In 43 339 patients with International Classification of Diseases, Tenth Edition schizophreniform or affective disorder diagnoses, 324 (0.75%) had any TOGH recorded (0.54% tactile, 0.24% olfactory, 0.06% gustatory hallucinations). TOGHs were associated with male gender, black ethnicity, schizophreniform diagnosis and higher disorder severity on Health of the National Outcome Scales. In fully adjusted models, tactile and olfactory hallucinations remained independently associated with prior mention of Z drugs (ORs 1.86 and 1.60, respectively).

CONCLUSIONS

We successfully developed a natural language processing algorithm to identify instances of TOGHs in the clinical record. TOGHs overall, tactile and olfactory hallucinations were shown to be associated with prior mention of Z drugs. This may have implications for the diagnosis and treatment of patients with comorbid sleep and psychiatric conditions.

Psychogenic Pruritus and Its Management

Chronic itching can be frustrating for patients and providers, and patients are not always willing to accept that their psychiatric health has an impact on their skin. Psychogenic pruritus is defined as itch not related to dermatologic or systemic causes. When a patient presents with pruritus, regardless of the presumed cause, the standard work-up should include a thorough history, dermatologic examination, and laboratory examinations or biopsies as needed. If no medical source is found, the provider must work in partnership with the patient to explore other causes and that may include acknowledging and treating underlying psychiatric conditions.

Itch and psyche: psychiatric aspects of pruritus

Itch, also referred to as pruritus, is an unpleasant cutaneous sensation provoking the desire to scratch. It is often an uncomfortable, subjective sensation responsible for decreased quality of life in a variety of psychodermatological conditions. Comorbid psychiatric conditions, including depression and anxiety, are frequently associated with itch and scratch cycle. The reciprocal and intricate relationship between the psyche and itch has been widely studied. The neurobiology of itch involves the complexity of specific mediators, itch-related neuronal pathways, and central processing of itch. The connection between itch and the psyche can be grouped under three headings: pruritic diseases with psychosocial sequelae, pruritic diseases aggravated by psychosocial factors, and psychiatric disorders causing pruritus. Itch and pain modulation go together in most circumstances and involve various substances including histamine, interleukins, protease-activated receptors, transient receptor potential receptors, opioids, and cannabinoids. The close interaction between keratinocytes and nerve endings modulating pain and itch also play a major role. Management of itch associated with its psychosomatic components is directed at an underlying cause and adopting a holistic approach to address not only dermatologic and somatosensory aspects, but also the cognitive, emotional, and psychosocial components. An integrated multidisciplinary team consisting of a dermatologist, psychiatrist, psychologist, and social worker is vital in addressing the multifaceted aspects of pruritus.

Delusional infestation. Ekbom´s syndrome in a 47-year-old woman. Case report

Introduction: Delusional infestation is a rare psychiatric disorder defined as a condition in which the patient has the unshakable belief and perception of being infested with parasites. Its treatment is difficult, and frequently includes antipsychotic medications (such as olanzapine or aripiprazole). Non-pharmacological treatment, particularly psychotherapy, can be used for less severe cases. Dermatologists and psychiatrists must take a multi-disciplinary approach (preferably in a psycodermatology dedicated clinic) since this type of patients sometimes refuse treatment.Case description: A 53-year-old female businesswoman describes a clinical history of five years of visual hallucinations, depressive symptoms, and generalized pruritus, along with the use of toxic substances to “clean” her skin and cloths. She reports similar symptoms in some relatives but they were not evaluated. Blood tests and analyses of the “specimen” brought by the patient were performed, yielding negative results. The patient had never been assessed by any specialist, and showed disoriented during the consultation. Follow-up was not possible due to the reluctance of the patient to follow the indications and seek psychiatric treatment. Moreover, the patient did not respond to further communication attempts.Discussion: Delusional infestation is an uncommon disease that endangers the patients and the people around them. Its treatment is difficult and long, and not conducting proper follow-up is a great risk. Its prevalence and incidence is variable and generally unknown. It can affect the patient, their next of kin, pets or the environment, and the “pathogen” can be a living organism or an inanimate object.  Conclusion: This case is important as it shows the hardships of treatment, adequate follow-up and care, as well as the need to improve how these patients are approached. Additionally, both classical and uncommon signs and symptoms could be observed as the patient stated that her relatives were affected (possible delusional infestation by proxy).

Higher severity of cocaine addiction is associated with tactile and somatic hallucinations

BACKGROUND

The aim of this study is to describe the features of cocaine-dependent patients who have had cocaine-induced tactile/somatic hallucinations (CITSH), and to analyze the association with addiction-related variables and psychiatric comorbidity, comparing patients with CITSH, patients with cocaine psychotic symptoms (CIP) and no CITSH, and patients without any psychotic symptom.

METHOD

A cross-sectional study was conducted in 767 cocaine-dependent patients in an outpatient treatment center for addictions. The following data were obtained: sociodemographic characteristics, CIP information, addiction-related variables and psychiatric comorbidity. A bivariate and multivariate analysis was performed.

RESULTS

Of the whole sample, 6.6% reported CITSH at some point of their lives, 48.4% had suffered some CIP other than CITSH, and 45% had not experienced any psychotic symptom. According to multivariate analysis, risk of overdose increases by 12.1 (OR) times the probability of having had CITSH compared patients with CIP-no-CITSH. Other variables associated to patients with CITSH were: age of drug use onset, presence of episodes of overdose, prevalence of psychotic disorder induced by cocaine. In general, in all variables studied, patients with CITSH presented worse clinical features (addiction variables and psychiatric comorbidity) than patients with CIP without CITSH and non-CIP group.

CONCLUSION

CITSH are usually associated with other psychotic symptoms induced by cocaine. The patients who experienced CITSH are more severe cases compared both with patients with CIP without CITSH and patients without CIP. Increased risk of overdose is an important issue in this type of patients.

Delusional Infestation

Although the practice of infectious diseases involves a broad range of surgical and medical disciplines, interactions with psychiatry are infrequent. Delusional infestation is a condition where an individual has a firmly fixed false belief that they have an infection. Delusional infestation challenges the infectious diseases specialist who must diligently rule out the presence of a true infection. However, perhaps, more importantly, we may need to initiate therapy with neuroleptic medications for which we may have little specific knowledge and experience. In this note we review the diagnosis and management of patients with delusional infestation.

Histological and hormonal changes in the European eel (Anguilla anguilla) after exposure to environmental cocaine concentration

The aim of this study was the assessment of histological and hormonal changes induced in the European eel from environmental concentrations of cocaine. Silver eels were exposed to 20 ng L(-1) of cocaine during 50 days; at the same time, control, vehicle control and two post-exposure recovery groups (3 and 10 days) were made. The general morphology of the skin and the intestine, and the plasma levels of prolactin, cortisol and dopamine were evaluated. In the skin, cocaine decreased the number and size of mucous cells, increased the thickness of the epidermis and altered the club cells and the basal lamina. In the intestine, cocaine increased the thickness of the epithelium and the number of mucous cells and reactivated the structure of the intestine and of the intestinal musculature. Moreover, cocaine increased plasma prolactin, cortisol and dopamine levels. These results suggest that cocaine induced histological changes, directly and/or through the hormonal changes observed. Considering the complex life cycle of the eel, the changes induced by cocaine in the skin, the intestine and the endocrine system could threaten the ability of the eel to successfully migrate and reproduce.

Distinction between forensic evidence and dermatological findings

The external examination after death requires knowledge in forensics/pathology, dermatology, as well as associated diseases and age-related alterations of the skin. This article highlights some findings with forensic evidence versus dermatological findings. The lectures in forensic medicine should be structured interdisciplinarily, especially to dermatology, internal medicine, surgery, pathology, and toxicology in order to train the overlapping skills required for external and internal postmortem examinations.

Facial cutaneous necrosis associated with suspected levamisole toxicity from tainted cocaine abuse

OBJECTIVE

This study aimed to illustrate the otorhinolaryngologic manifestations of levamisole toxicity and illuminate the features of this diagnosis.

METHODS

We describe a case of a known cocaine abuser with suspected levamisole toxicity who developed cutaneous necrosis of the cheeks, earlobes, nose, upper and lower lip, and the midline hard palate. We also review the existing clinical literature about this emerging phenomenon.

RESULTS

Levamisole is a common adulterant in cocaine distributed in the United States and has been reported to cause microvascular thrombosis and vasculitis with resultant skin necrosis in cocaine abusers. The distribution of skin findings characteristically involves the cheeks, earlobes, nose, lips, and hard palate and responds variably to cessation of cocaine use. In its most severe cases, immune suppression and/or surgical debridement may be required.

CONCLUSION

Levamisole toxicity can frequently involve the ears, nose, and throat tissues. Otorhinolaryngologists should recognize these manifestations to expeditiously diagnose and manage this condition. Failure to do so promptly can lead to complications that may necessitate reconstructive or amputation surgery.

Psychosomatic factors in pruritus

Pruritus and psyche are intricately and reciprocally related, with psychophysiological evidence and psychopathological explanations helping us to understand their complex association. Their interaction may be conceptualized and classified into 3 groups: pruritic diseases with psychiatric sequelae, pruritic diseases aggravated by psychosocial factors, and psychiatric disorders causing pruritus. Management of chronic pruritus is directed at treating the underlying causes and adopting a multidisciplinary approach to address the dermatologic, somatosensory, cognitive, and emotional aspects. Pharmcotherapeutic agents that are useful for chronic pruritus with comorbid depression and/or anxiety comprise selective serotonin reuptake inhibitors, mirtazapine, tricyclic antidepressants (amitriptyline and doxepin), and anticonvulsants (gabapentin, pregabalin); the role of neurokinin receptor-1 antagonists awaits verification. Antipsychotics are required for treating itch and formication associated with schizophrenia and delusion of parasitosis (including Morgellons disease).

Cocaine-induced vasculitis: clinical and immunological spectrum

Levamisole-contaminated cocaine has recently been recognized in North America and Europe, and its use is associated with a variety of clinical and autoimmune abnormalities. The clinical characteristic seems to be the presence of a painful purpuric skin rash that predominantly affects the ear lobes and cheeks, often accompanied by systemic manifestations including fever, malaise, arthralgias, myalgias, and laboratory abnormalities, for example leukopenia, neutropenia, positive ANA, ANCA, and phospholipid antibodies. Most of these manifestations can be seen with the use of either drug, especially levamisole. There is no specific therapy, and discontinuation of its use is followed by improvement. Prednisone and immunosuppressive therapy may be needed at times. Further use of the drug is characterized by recurrence of most of the complaints.

Levamisole-induced vasculopathy: a report of 2 cases and a novel histopathologic finding

Although cocaine-induced pseudovasculitis and urticarial vasculitis have been reported in the past, levamisole-induced vasculopathy with ecchymosis and necrosis, termed here LIVEN, has only recently been described in association with cocaine use. Levamisole, a veterinary antihelminthic agent used previously as an immunomodulating agent, is present as a "cutting agent" in approximately two-thirds of the cocaine currently entering the United States. Levamisole is believed to potentiate the effects of cocaine and may also be used as a "signature" for tracing its market distribution. Herein, we report 2 cases of LIVEN in patients with histories of chronic cocaine use. In both the cases, a temporal association with neutropenia preceding the eruption was noted. A novel histopathologic finding present only in the second case was the presence of extensive interstitial and perivascular neovascularization. Our 2 cases reaffirm that neutropenia may precede the cutaneous eruption of LIVEN. Case 2 extends the spectrum of histopathologic findings to include the novel phenomenon of neovascularization-hitherto unreported in this entity.

Vasculopathy, hematological, and immune abnormalities associated with levamisole-contaminated cocaine use

OBJECTIVES

To report 4 cases of cocaine-related purpura and to review previously reported cases of levamisole, levamisole-contaminated cocaine, and cocaine-induced vasculopathy.

METHODS

We describe 4 patients suspected of vasculopathy associated with levamisole-tainted cocaine use. A retrospective review of the literature was performed using the PubMed, PubJet, MD consult, and Cochrane review databases.

RESULTS

Four cases (2 females and 2 males), 46 to 55 years of age, presented with cocaine-related purpura, mainly affecting the ears, neutropenia, and autoantibodies. Skin biopsies revealed a mixed pattern of leukocytoclastic vasculitis and microvascular thrombosis in 2 cases, and pure thrombosis in the third case. The mixed vasculopathic pattern in association with neutropenia, both known adverse effects of levamisole, and levamisole positivity in 2 cases point to this compound as the true etiologic agent in our patients. Eleven cases of levamisole-contaminated cocaine-induced vasculopathy have been described in the English literature. Among these, 10 were females. Age range was 22 to 57 years. Urine levamisole positivity was tested and confirmed in 3 of the 11 cases. The clinical characteristics, laboratory features, histology, treatment, and recovery rates were compared for the published cases of levamisole, levamisole-contaminated cocaine, and cocaine-induced vasculopathy.

CONCLUSIONS

Adulterated cocaine abuse is an increasingly recognized phenomenon in North America. Levamisole is among the many contaminants that have been detected in seized cocaine throughout North America and Europe. Recent reports described an association between levamisole-tainted cocaine and purpuric skin rash, neutropenia, and the presence of autoantibodies.

[Abstinence from cocaine after long-term addiction]

BACKGROUND

Experimental data strongly suggest that in animal and probably in man, noradrenergic and serotoninergic become uncoupled during repeated consumption of drugs of abuse, strongly suggesting that different drugs share common mechanisms for drug-dependence. Using cocaine-dependence as model of strong addiction we speculate that careful analysis of psychic adjustments in patients who experience prolonged abstinence could be a useful tool for patient's care.

AIM

The aim of this retrospective study was first to establish similarities in patients' histories concerning modes of entrance, circumstances favouring the stopping, and modality of withdrawal. Secondly, we analysed the different ways used by subjects to substitute their cocaine-dependence.

PATIENTS AND METHODS

Cocaine-dependent subjects who had succeeded in supporting abstinence for at least 12 months without consumption were evaluated retrospectively by a face-to face interview.

RESULTS

We obtained a list of circumstances associated with entries and exit from cocaine-dependence. Second, when seeking for similarities in addictive behaviour, before and after, between cocaine users, we proposed to classify patients according to the strength in their addictive dominant trait between strong, moderate, mild, or absence of addictive behaviour. For didactic aims, purposes are illustrated by clinical vignettes.

CONCLUSIONS

This retrospective study allows us to clear arbitrarily four types of psychical modifications associated with prolonged abstinence in cocaine-dependent patients. Prospective clinical studies are clearly needed to standardize and to validate these clinical criteria.

An oral ulceration associated with Morgellons disease: a case report

Morgellons disease is a psycho-dermatologic condition in which patients report fibers or filaments "growing" out of their skin. This case report highlights an oral ulceration in a young woman associated with Morgellons disease, a condition that has not been previously described in the dental literature. An increasing number of individuals are self-reporting this condition and oral health care providers must be familiar with this disorder.

Skin alterations due to illegal drug abuse

Drug abuse is associated with a wide variety of skin alterations. Being aware of the typical signs and symptoms of the drug addicts' skin is of special importance to dermatologists, even though dermatologists are commonly not involved in the treatment of these patients. There is yet a chance for dermatologists to identify drug abusers early by to some extent specific cutaneous signs and after exclusion of several other etiological factors, so that this will lead to further treatment through the respective specialists. The objective of this paper is to draw particular attention to typical skin lesions and diseases which may be associated with drug abuse.

Delusional infestation

This papers aims at familiarizing psychiatric and nonpsychiatric readers with delusional infestation (DI), also known as delusional parasitosis. It is characterized by the fixed belief of being infested with pathogens against all medical evidence. DI is no single disorder but can occur as a delusional disorder of the somatic type (primary DI) or secondary to numerous other conditions. A set of minimal diagnostic criteria and a classification are provided. Patients with DI pose a truly interdisciplinary problem to the medical system. They avoid psychiatrists and consult dermatologists, microbiologists, or general practitioners but often lose faith in professional medicine. Epidemiology and history suggest that the imaginary pathogens change constantly, while the delusional theme "infestation" is stable and ubiquitous. Patients with self-diagnosed "Morgellons disease" can be seen as a variation of this delusional theme. For clinicians, clinical pathways for efficient diagnostics and etiology-specific treatment are provided. Specialized outpatient clinics in dermatology with a liaison psychiatrist are theoretically best placed to provide care. The most intricate problem is to engage patients in psychiatric therapy. In primary DI, antipsychotics are the treatment of choice, according to limited but sufficient evidence. Pimozide is no longer the treatment of choice for reasons of drug safety. Future research should focus on pathophysiology and the neural basis of DI, as well as on conclusive clinical trials, which are widely lacking. Innovative approaches will be needed, since otherwise patients are unlikely to adhere to any study protocol.