Fabricated or Induced Illness (FII) in Children – The Letby Case

Following a 10-month trial, the nurse Lucy Letby was convicted of the crimes by a jury. The 33-year-old former neonatal nurse was convicted in Aug 2023 of seven murders and attempting to murder six others in the neonatal unit of the Countess of Chester Hospital in 2015 and 2016.  She will face a retrial on an outstanding charge of attempting to murder a baby girl in June 2024.  Letby is now known as Britain’s worst child serial killer.


The trail judge Mr Justice Goss told the jurors they did not have to be sure of the motive or motives for deliberately harming a baby, He said: “Motives for criminal behaviour are sometimes complex and not always clear. You only have to make decisions on those matters that will enable you to say whether the defendant is guilty, or not, of the particular charge you are considering.”

I am sure many of us working in professional safeguarding have thought Letby’s motive was Fabricated or Induced Illness in which a carer can physically harm a child. As published in the Independent on 18 Aug 2023, psychological profiles were not sourced as the investigation team had not found any evidence to do so.  This horrific case made me think back to my police career and how many cases of Fabricated or Induced Illness (FII) I had been involved in as part of a Child Abuse Investigation Team. 

FII is very complex and perceived to be rare, as experts still do not have a clear picture of how this form of child abuse occurs. This blog takes a closer look at the current research, guidance, and literature available on FII and Perplexing Presentations (PP).  I strongly believe ALL safeguarding training needs to include FII and PP and I have done so in my courses for many years.


Since Professor Sir Roy Meadow first described the condition ‘Munchausen Syndrome by Proxy’ (MSP) in 1977, a number of terms have been introduced, all of which essentially refer to the same entity.  The Royal College of Paediatrics and Child Health (RCPCH) adopted the term ‘Fabricated or Induced Illness by Carers’ (FII) in 2002, now this is the correct term widely used in the UK by professionals. However, there is a debate regarding the terminology, and I still hear professionals in training refer to this as Munchausen Syndrome by Proxy (MSP) as it is known in the USA.

The Royal College of Paediatrics’ and Child Health (RCPCH) published new guidance in March 2021 called Perplexing Presentations (PP) Fabricated or Induced Illness (FII) in Children >

This guidance, provides best practice advice for paediatricians in the medical management of PP and FII cases to obtain better outcomes for children and has been adopted by Safeguarding Children’s Partnerships and Healthcare.  I am still surprised how little is known about this guidance and the terminology used.

It is widely recognised and acknowledged across the health, police and social care economies that Fabricated and Induced Illness by Carers (FII) is one of the most challenging areas of Child Protection in which to work. Practitioners have to make extremely exacting professional judgements and can experience various levels of stress when addressing the complex issues inherent in such cases.

The definition of Fabricated or Induced illness (FII)

FII is a clinical situation in which a child is, or is very likely to be, harmed due to parent(s)/caregivers’ behaviour and action, carried out to convince doctors that the child’s state of physical and/or mental health and neurodevelopment is impaired (or more impaired than is actually the case).

FII results in physical and emotional abuse and neglect, as a result of parental actions, behaviours or beliefs and from doctors’ responses to these. The parent does not necessarily intend to deceive, and their motivations may not be initially evident.

The guidance makes a point that it’s important to distinguish between FII and non-accidental Injury (NAI)/ physical abuse, paediatric guidance says, “In order for this physical abuse to be considered under FII, evidence will be required that the parent’s motivation for harming the child is to convince doctors about the purported illness in the child and whether or not there are recurrent presentations to health and other professionals. This particularly applies in cases of suffocation or poisoning.”

The term Perplexing Presentations (PP) has been introduced in this guidance when there are alerting signs of possible FII (not yet about to significantly harm).  Alerting signs may be discrepancies between reports, presentations of the child, independent observation of the child, implausible descriptions and unexplained findings or parental behaviour.

A third key term referred to in RCPCH guidance is Medically Unexplained Symptoms (MUS) where the child genuinely complains of unexplained symptoms but are not explained by any pathology but with likely underlying factors in the child (Psychosocial nature).

Hobbs et al. refer to FII as ‘a deceptive, secretive and interactional liaison which has at its centre the child, the doctor or other professional and the perpetrator’.

Is FII as Rare as we Think?

FII is one of the most complex forms of child abuse and recovering data is difficult which makes it hard to understand the prevalence.  Many experts suggest this is very rare and opinions vary.  Other experts suggest that the guidance and literature focuses on the more severe cases and therefore FII appears to be rarer than it is.

Alerting Signs of FII & PP

Within the RCPCH guidance there is a flowchart  explaining the definitions and the response required by professionals, which isn’t necessarily an immediate referral to social care.

RCPH guidance states “Unless there is significant risk of immediate, serious harm to the child’s health or life, the need for sharing information between different professionals involved in the child’s life should be discussed with the child/young person and their parents”.

Alerting Signs in the Child include:

  • Reported physical, psychological, or behavioural symptoms and signs not observed independently in their reported context.
  • Unusual results of investigations (e.g., biochemical findings, unusual infective organisms).
  • Inexplicably poor response to prescribed treatment.
  • Some characteristics of the child’s illness may be physiologically impossible e.g., persistent negative fluid balance, large blood loss without drop in haemoglobin.
  • Unexplained impairment of child’s daily life, including school attendance, aids, social isolation.

Harm to the Child

  • The child undergoes repeated, unnecessary medical appointments, examinations, investigations, which are often distressing to the child.
  • This can affect the day-to-day development of the child.
  • This may affect the child’s wellbeing and psychological health.

Alerting Signs of Parent Behaviour include: 

  • Parents’ insistence on continued investigations instead of focusing on symptom alleviation when reported symptoms and signs not explained by any known medical condition in the child. 
  • Parents’ insistence on continued investigations instead of focusing on symptom alleviation when results of examination and investigations have already not explained the reported symptoms or signs.
  • Repeated reporting of new symptoms. 
  • Repeated presentations to and attendance at medical settings including Emergency Departments. 
  • Inappropriately seeking multiple medical opinions. 
  • Providing reports by doctors from abroad which are in conflict with UK medical practice.
  • Child repeatedly not brought to some appointments, often due to cancellations.

For the full list please refer to the RCPCH Guidance >

Parent / Caregiver Motivation & Behaviour of FII

According to the RCPCH, FII is based on the parent’s underlying need for their child to be recognised and treated as ill or more unwell/more disabled than the child actually is (when the child has a verified disorder, as many of the children do). FII may involve physical, and/or psychological health, neurodevelopmental disorders and cognitive disabilities. There are two possible, and very different, motivations underpinning the parent’s need: the parent experiencing a gain and the parent’s erroneous beliefs. It is also recognised that a parent themselves may not be conscious of the motivation behind their behaviour. Both motivations may be present although usually one predominates.

Key findings:

  • The mother is nearly always involved or is the instigator of FII.
  • The father may be unaware, suspicious but side-lined or may be actively involved.
  • Rarely foster carers have been involved in FII.
  • Parents experience some sort of gain, psychologically or material.
  • Some parents benefit from sympathetic attention.
  • Parents who struggle with the management of their child seek inappropriate mental health diagnosis such as attention deficit hyperactivity disorder (ADHD) OR Autism Spectrum Disorder
  • Material gains include financial support for the care of their child.

For more information please refer to the RCPCH Guidance >

Royal College of General Practitioners (RCPCH) Survey

A survey was completed in 2018 by 216 members of the Royal College of General Practitioners (RCPCH) 92% of the 216 recalled seeing at least one presentation of Perplexing Presentations over a 12-month period and 30% recalled seeing 5.

The survey highlighted 69 different condition presentations. The most common presentations were:

  • Feeding difficulties
  • Challenging behaviour
  • Musculoskeletal symptoms and gait disorders

Child Abuse Review (CAR) Survey

A research study published in the Child Abuse Review (CAR) Journal on the 13th of December 2020 was seeking information from 147 local safeguarding Partnerships on FII. There was a low response of 18 out of 147.  Surprisingly, 17 challenges were identified from 18 respondents, which included the lack of training, poor multi-agency collaboration, and uncertainties and anxiety amongst professionals tasked with identifying FII.  More information here >


Most concerning is that some charities are raising awareness that parents of disabled children are increasingly being accused of FII (published article 25th April 2023 Children and Young People Now).  PANS PANDAS UK is a charity supporting children and families living with neuropsychiatric conditions PANS and PANDAS.  PANS and PANDAS are conditions that often appear very suddenly and affect the physical and mental health of children and young adults. They develop in the wake of common infections (such as Covid-19, chicken pox, influenza, or strep A in PANDAS cases), when the infection subsequently causes a misdirected immune response and/or brain inflammation.  In a PANS PANDAS UK survey of 217 parents, 5% reported formal accusations of FII, 12% reported formal safeguarding procedures.

PANS PANDAS UK has produced a guide relevant to healthcare, social work and educational professionals who may come into contact with children and young people presenting with acute onset neuropsychiatric symptoms. It introduces the medical disorders termed PANS and PANDAS and explores the reasons why a disproportionate number of UK families living with these conditions are subject to safeguarding referrals and allegations of Fabricated or Induced Illness (FII).  PANS, PANDAS & Fabricated or Induced Illness: A Guide for Social Work, Healthcare & Education Professionals 2023 >

Professor Luke Clements, Cerebra Professor at Law and Justice in Leeds University undertook a survey last July, with disabled children’s charity Cerebra, whereby 380 parents reported being accused of FII, the majority from the NHS followed by schools and social services. 

Fiona Gullon-Scott, doctor of psychology at the University of Newcastle, who co-authored a recent academic paper on FII and PP, says that allegations of FII are reported to have “increased substantially” against parents of autistic children and children with SEND, with families being “pulled into the child protection system” despite “little or no evidence” to substantiate the claims.

In 2022 the British Association of Social Workers (BASW) published guidance on Fabricated and Induced Illness or Perplexing Presentation’s.  BASW Guide > This guidance says that the behaviour of autistic and neurodivergent children can often be mistaken for FII as is the case in multisystemic conditions such as Myalgic Encephalomyelitis and Ehlers Danlos Syndrome. 

Recommendations for Social Workers Include:

  • Social workers need to understand that complex investigations in suspected FII can often be due to rare or misdiagnosed illnesses.
  • It is essential to work with parents /caregivers and determine what support is required and to ensure specialists with knowledge of relevant conditions are involved.
  • Social workers need to accept the potential for interprofessional differences about FII and be confident in their skills to promote a social perspective.

Within this guide is an excellent checklist for practitioners which is co-produced by parent/carer feedback and incorporates questions for the practitioner to consider before moving into the child protection arena.


Researching convictions for FII can prove to be very difficult as they rarely end up in the criminal courts unless severe.  Here is a link to the learning form one of the reginal and national serious case reviews published in July 2023: Teeside Safeguarding Adults Board >

From my practitioners experience over 24 years, when investigating suspected FII, I have encountered cases of FII.  For example, other siblings in the family who had similar health issues which have been missed as possible FII. I have known parents fabricate their own illnesses such as diabetes and a heart condition, and one fabricate a disability for financial gain.  I have known a young mum who was struggling to cope with a premature baby, physically abuse her young child.  I have known a parent fabricate sexual abuse of their child, and mental health conditions of their children resulting in the children receiving medication without any assessment.  


It is clear from the guidance and literature that I have researched that FII is very complex, and we still do not have a clear picture of how common this form of child abuse is.

What is also clear is misdiagnosis can happen with children with medically unexplained illnesses or children with disabilities. This means that professionals need to engage with experts in this field for a clear assessment of the child.

The Nursing and Midwifery Council (NMC) has seen a surge in referrals and enquiries in the aftermath of the conviction of nurse Lucy Letby, as fitness to practise (FtP) cases hit a record high.  The regulator’s caseload now stands at 5,500.

Awareness & Training

I strongly believe safeguarding training needs to include FII and Perplexing Presentations, I have always included this in all of my training courses and have experience over many decades in this field.  FII and PP will be thoroughly covered in our next online training course next week.  Please see the below or contact me to find out more.

Online 2-day Combined Safeguarding Children & Adults Complex (Level 4) Training Mon 27th & Tues 28th Nov 2023

Online tickets: https://safeguardingcombined.eventbrite.co.uk/

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