Electronic Letters to:

REVIEW ARTICLES:
Peter Lepping, Ian Russell, and Roland W. Freudenmann
Antipsychotic treatment of primary delusional parasitosis: Systematic review
The British Journal of Psychiatry 2007; 191: 198-205 [Abstract] [Full text] [PDF]
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Electronic letters published:

[Read eLetter] Old problem, new name?
Kate S Robertson   (12 October 2007)
[Read eLetter] Aripiprazole in the treatment of Primary Delusional Parasitosis
Vinesh Narayan, Muhammad Ashfaq, Peter M. Haddad   (9 April 2008)
[Read eLetter] Considerations of second generation antipsychotics in the treatment of delusional parasitosis
Peter Lepping, Roland W Freudenmann   (2 July 2008)
[Read eLetter] DP, Very rare or ill reported condition......
Ravimal Galappaththi   (24 January 2009)

Old problem, new name? 12 October 2007
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Kate S Robertson,
Staff grade psychiatrist
Huntercombe Hospital- Stafford

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Re: Old problem, new name?

kate.robertson{at}doctors.org.uk Kate S Robertson

The review by Lepping et al (2007) of drug treatments for delusional parasitosis emphasises not only the lack of good quality evidence for treatment with atypical antipsychotics, but also the difficulty in engaging and treating people with this disorder.

I would like to draw attention to the emerging phenomenon of ‘Morgellons’. The name is apparently derived from Sir Thomas Browne (‘…Endemial Distemper of little Children in Languedock, called the Morgellons…’ Letter to a Friend, 1690), and was then more recently applied to the medically unexplained symptoms suffered by the child of a biologist in the United States. The descriptions of symptoms and possible causes on the Morgellon research foundation website contain marked similarities to definitions of delusional parasitosis; however, the philosophy of the site is clear- ‘we don’t know what it is but it is not that’. Lepping et al also rightly mention the possibility of alienation of sufferers and the possibility of resort to dangerous self therapies; worryingly, ‘Morgellons’ is described in children as well as adults.

The risks of overenthusiastic ascription of psychiatric causes to physical symptoms have been well documented (eg Slater, 1965), and perhaps in no other branch of medicine is it so important to keep an open mind. Nonetheless, it is also possible that ‘Morgellons’ will on occasion serve as a label for those who are truly deluded as to the presence of parasites under their skin. Indeed, it has been argued (by dermatologists) that ‘Morgellons’ be used as a diagnostic label as an aid to establishing rapport (Murase et al) before antipsychotic treatment.

Although ‘Morgellons’ appears to be limited to the United States at present, with all but universal internet access, and in the age of 'cyberchondria', it will be interesting to see if the phenomenon spreads.

Dr Kate Robertson, Staff grade psychiatrist Huntercombe Hospital- Stafford Ivetsey Bank Wheaton Aston Staffordshire ST19 9QT

tel. 01785 840000 fax. 01785 842192

No competing interests

References: Lepping P, Russell I, Freudenmann RW; Antipsychotic Treatment of Primary Delusional Parasitosis, The British Journal of Psychiatry (2007) 191: 198- 205

Slater ET; Diagnosis of ‘hysteria’. BMJ 1965;i:1395 -9

Murase JE, Wu JJ, Koo J; Morgellons disease: a rapport-enhancing term for delusions of parasitosis, Journal of the American Academy of Dermatology, 2006 Nov;55(5):920-2

Aripiprazole in the treatment of Primary Delusional Parasitosis 9 April 2008
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Vinesh Narayan,
Specialist Registrar
MRCPsych,
Muhammad Ashfaq, Peter M. Haddad

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Re: Aripiprazole in the treatment of Primary Delusional Parasitosis

vineshnarayan{at}yahoo.com Vinesh Narayan, et al.

The review by Lepping et al(1) points out the difficulty of engaging patients with primary delusional parasitosis (PDP) in psychiatric treatment due to their poor insight. Our clinical experience fully supports this. The authors emphasise the lack of randomised controlled studies in this field and the limited, but promising, anecdotal literature on the use of atypical antipsychotics. Their systematic review did not identify any reports of aripiprazole in the treatment of PDP. However since this review was accepted for publication, a case report has appeared reporting the successful use of aripiprazole in an 85-year-old woman with PDP(2).

Aripiprazole has a unique pharmacological profile that includes partial agonist activity at dopamine D2 and serotonin 5-HT1A receptors. It has a favourable side effect profile relative to other antipsychotics(3). It is not sedating and has little propensity to cause weight gain, extrapyramidal symptoms, prolactin elevation and metabolic disturbance. However it can cause nausea and akathisia in some patients. The favourable tolerability profile may be a particular benefit in PDP as these patients are often reluctant to consider antipsychotic treatment and tolerate medication poorly.

Aripiprazole has a long half-life (approximately 60 hours) compared to other oral antipsychotics(4), which means that occasional missed doses are less likely to impact on clinical outcome. Consequently aripiprazole may be particularly useful when intermitted adherence with medication is a problem, a situation often encountered in PDP. Interestingly, in the 5 main studies of antipsychotic treatment of PDP identified by Lepping et al1, the highest remission rate (73%) was in the only study that assessed antipsychotic depots(5). Although the small sample sizes limit the value of cross-study comparisons, this result is consistent with the view that medication adherence is poor in PDP and that treatments that can overcome this, in this case a depot antipsychotic, can lead to better outcomes.

In summary, although further evidence is needed to establish the efficacy of aripiprazole in PDP, it seems reasonable to consider this drug when discussing treatment choices with patients with PDP.

Competing interests: PMH has received fees for lecturing and consultancy from Bristol Myers Squibb, who manufacture aripiprazole, and the manufacturers of various other antipsychotics.

Vinesh Narayan SpR in General Adult Psychiatry Greater Manchester West Mental Health NHS Foundation Trust vineshnarayan@yahoo.com

Muhammad Ashfaq Staff Grade in General Adult Psychiatry Greater Manchester West Mental Health NHS Foundation Trust

Peter M. Haddad Consultant Psychiatrist Greater Manchester West Mental Health NHS Foundation Trust

References: 1. Lepping P, Russell I, Freudenmann RW. Antipsychotic treatment of Primary delusional parasitosis. The British Journal of Psychiatry 2007; 191: 198- 205 2. Rocha FL, Hara C. Aripiprazole in delusional parasitosis:case report. Progress in Neuro-psychopharmacology and Biological Psychiatry 2007; 31: 784-786 3. Haddad PM, Sharma SG. Adverse effects of atypical antipsychotics: differential risk and clinical implications. CNS Drugs 2007: 21(11): 911- 36. 4. Mallikaarjun S, Salazar DE, Bramer SL. Pharmacokinetics, tolerability, and safety of aripiprazole following multiple oral dosing in normal healthy volunteers. J Clin Pharmacol. 2004; 44(2): 179-87 5. Frithz A. Delusions of infestation: treatment by depot injections of neuroleptics. Clinical and Experimental Dermatology 1979; 4: 485-488

Considerations of second generation antipsychotics in the treatment of delusional parasitosis 2 July 2008
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Peter Lepping,
Consultant Psychiatrist, Honorary Senior Lecturer, Associate Medical Director
University of Wales Bangor, North East Wales NHS Trust,
Roland W Freudenmann

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Re: Considerations of second generation antipsychotics in the treatment of delusional parasitosis

peter.lepping{at}new-tr.wales.nhs.uk Peter Lepping, et al.

Dear Sir,

We thank our colleagues Narayan et al for their contribution (eLetter to British Journal of Psychiatry, 9 April 2008) to the discussion around the antipsychotic treatment of primary delusional parasitosis (DP) referring to our recent systematic review in this journal (Lepping, Russell & Freudenmann, 2007).

Narayan et al suggest that the pharmacokinetics (half-life of 60-80 hours) and side effect profile of aripiprazole may make it particularly interesting for the treatment of DP where adherence to and engagement with treatment are the most significant challenges. They mention a case report of an 85 year-old woman with primary DP, which fully responded to aripiprazole (Rocha & Hara, 2007). Age-adapted doses of 15, later 7.5 mg daily led to full resolution of symptoms after olanzapine had to be stopped because of severe hyponatraemia and pimozide had been abandoned because of extrapyramidal symptoms. Recently Kumbier & Höppner published a second case of aripiprazole use resulting in an almost full remission of symptoms (Kumbier & Höppner, 2007); however, the DP syndrome was secondary to paranoid schizophrenia and not a primary delusional disorder.

It is indeed interesting that our own systematic review in this journal showed that the best response rates were achieved with first generation depot antipsychotics, although this finding was based on a single small study by Frithz, published in 1979. However, other first generation antipsychotics with relatively long half-lives such as pimozide (half-life of 55 hours) or haloperidol (half-life 12-36 hours) did not differ from those first generation antipsychotics with shorter half-lives. Experience with other second generation antipsychotics with long half- lives are limited to one case with partial remission to sertindole (half- life 55-90 hours) (Yorston, 1997) and one recent case treated with paliperidone (half-life 24 hours) from our group (Freudenmann, Kühnlein, Lepping, et al). However, both patients suffered from a DP syndrome secondary to brain pathology or a severe medical condition. Thus, evidence for the use of antipsychotics with long half lives in DP is very limited, in particular in primary DP, where it is limited to the one case treated with aripiprazole (Rocha & Hara, 2007).

Whilst pharmacokinetic considerations are obviously an important aspect when choosing an antipsychotic for the treatment of DP, efficacy and tolerability are at least equally, if not more important. The level of efficacy of second generation antipsychotics in DP is less than certain, although the number of cases reporting positive effects is growing constantly. Our own review showed that only 25% of patient treated with a second generation antipsychotic achieved full remission in primary DP.

Two published cases are too few to enable us to make a judgement on the efficacy of aripiprazole in DP, although every case report is welcome because it increases our knowledge. The side effect profile of aripiprazole may be advantageous with regard to the development of metabolic syndrome, but this is often less important in DP because of the often short period of time that patients agree to take medication. Furthermore, the common side effect of insomnia is a real problem with aripiprazole in a patient group that already suffers from agitation and insomnia because of persistent itching.

We therefore agree that medications with long half-life are theoretically promising in DP, as is true for all disorders with poor insight and a tendency to intermittent non-adherence. However, we do not agree that the current evidence available for aripiprazole makes it the substance of choice among the group of second generation antipsychotics in DP despite its favourable pharmacokinetic profile and low risk of metabolic and cardiac complications. There are substantially more successful reports on risperidone (more than n = 30) and olanzapine (more than n = 15) as well as our own positive experience with amisulpride than case reports on aripiprazole in both primary and secondary DP. However, clinical studies, not case reports, will be needed to further establish second generation antipsychotics in DP, and show their individual effects in this syndrome.

Corresponding author: Dr. Peter Lepping, Honorary Senior Lecturer (University of Wales Bangor), Consultant Psychiatrist and Associate Medical Director (North East Wales NHS Trust) Roland W. Freudenmann (University of Ulm)

Declaration of Interest: PL has received honoraria for lecturing from Lilly and Bristol-Myers Squibb, producers of aripiprazole. He has been partially funded by Lilly to attend a conference in 2007. This activity was fully within the rules of CR148. RWF has nothing to declare.

References:

Freudenmann, R. W., Kühnlein, P., Lepping, P., et al Secondary delusional parasitosis treated with paliperidone. Clin Exp Derm (in press). Kumbier, E. & Höppner, J. (2007) Neuroleptische Behandlung des Dermatozoenwahns. Erste Erfahrungen mit Aripiprazol [The neuroleptic treatment of delusional parasitosis : First experiences with aripiprazole.]. Hautarzt, published online Nov 18 2007, DOI 10.1007/s00105 -007-1438-2. Lepping, P., Russell, I. & Freudenmann, R. W. (2007) Antipsychotic treatment of delusional parasitosis: systematic review. Br J Psych, 191, 198-205. Rocha, F. L. & Hara, C. (2007) Aripiprazole in delusional parasitosis: Case report. Prog Neuropsychopharmacol Biol Psychiatry, 31, 784-786. Yorston, G. (1997) Treatment of delusional parasitosis with sertindole [letter]. Int J Geriatr Psychiatry, 12, 1127-1128.

DP, Very rare or ill reported condition...... 24 January 2009
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Ravimal Galappaththi,
DCP, MRCPsych
Sri Lanka

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Re: DP, Very rare or ill reported condition......

ravimalg{at}hotmail.com Ravimal Galappaththi

I read this article with much interest and would like to share my experience. Due to the rarerity of presentation and not being due to diagnosed, DP is not well reported across medical journals and community. The exact incidence in not known. It is important to bear in mind that DP is a psychiatric symptom rather than a diagnosis, the symptom of being convinced that the person is being infested by some form of parasites.

We have recently reported two presentations suggestive of DP. Both cases initially have presented to their local GPs and first were treated with anti histamines and the second with vermox. Both patients did not improve with treatment and continued to experience the skin irritation and showed an abnormal conviction that parasites were causing them. Both patient’s fixity and unshakability of beliefs were within the definition of a delusion. In one of the clients, development of conviction to delusional intensity was gradual mainly contributed by the pruritic skin irritation, and other was delusional at onset. Of note is that there was evidence of some degree of sharing of the belief by the partner of one of the clients. Shared delusions were documented in 5-15% of patients with DP. As patients with DP mostly contact dermatologist, GPs and public health doctors, wider knowledge among the medical doctors about the condition is essential. Documented cases before identification have varied between 2 months to 35 years, with a mean duration of 3.5 years (2), how ever both our clients were in remission within 6 weeks, after treatment with Risperidone.

Bhatia et al concluded that 88% of cases with DP were above 45 years and majority were women. Both of our patients were women in their mid fifties. Some studies report onset is insidious with a chronic course; however DP occurred suddenly in both our clients. This could have been due to prompt psychiatric diagnosis and treatment. It is now known that early diagnosis and antipsychotic treatment makes a difference, and this has been well documented in a systemic review in British journal of psychiatry. (1) In both our patients’ remission of symptoms was noted within few days to two weeks of starting a trial of low dose risperidone. In both patients there was no significant past psychiatric history, and screening for psychiatric disorders at the time of assessment was negative. However we were unable to exclude an adjustment disorder, given the history of precipitating stressors, and mixture of affective and anxiety symptoms at the time of presentation. Medical causes were excluded with biochemical screen, MRI studies ect..One of them was significantly socially isolated, which is a documented relationship in many clients. Interestingly both patients had a history of atopic allergy, obsessive compulsive traits but I couldn’t capture literature stating the relationship.

DP probably appear to be related to neurochemical change, the very reason why DP is precipitated by, cocaine “cocaine bug”, amphetamines, alcohol ect. This theory is also confirmed by its coincidence with axis 1 disorders such as schizophrenia, major depression, and sensory impairment, and also by neurotransmitter secreting space occupying lesions in the brain.

DP presents a therapeutic challenge to both patient and the treating physician. Although a fair number of DP patients have a contestable belief on infestation, they do resist the suggestion that condition is psychiatric. There for its paramount that psychiatrist would not collude or challenge the delusions at least initially. It’s much therapeutic to accept the patients distress and and create a window of opportunity where alliance can be established and work with the patient to accept antipsychotic medication at an earlier stage of disease. Patient’s sense of isolation must be reduced. Patients sense of helplessness need to be born in mind and its not uncommon for these patient to feel suicidal in context of unresolving and frustrating symptoms. A sensible approach and engagement should prevent ‘doctor shopping’ which will reduce the risk of medicalising the problem.

DP is not a culture bound symptom but disorder may have a different character in Asian compared to Caucasian counterparts. For example Indian patients from madras was younger (mean age 36.4), and experienced shorter duration of symptoms (mean 10.4 months). Both of our clients had a complete remission of symptoms in 6 weeks, evidenced by improvement in cognition, mood, social functioning, and reduction of abnormal perceptions and attached delusions. Remarkable improvement in insight with attribution of symptoms to possible stress was evident in both clients after 2-3 weeks.

Practical Points 1. DP is most likely to be a common presentation though less encountered in psychiatric practice and could present to a variety of medical services

2. Basic understanding of the condition and treatment is necessary by practitioners of all medical Specialities

2. Early referral of chronically symptomatic patients to liaison and other psychiatric services will certainly be helpful to reduce the patient distress and reduce the chronicity

3. Antipsychotics seem to be effective in most cases with DP, contrairy to delusional disorders possibly indicating a different neuro- biological basis which needs further testing. This is especially evident with Primary DP.

4. Finally, more randomized control trials or Meta analysis of current evidence is needed to strengthen the evidence base

References: 1. Peter Lepping, Ian Russell, and Roland W. Freudenmann, Antipsychotic treatment of primary delusional parasitosis: Systematic review, The British Journal of Psychiatry, Sep 2007; 191: 198 - 205.

2. Delusional Parasitosis: case series of 8 patients and review of litereture, JY Thong, DCW Aw, HL Chan, Ann Acad Medi. Singapore 2004;33:89 -94