Chediak-Higashi syndrome

General paediatrics, Immunology

A neutrophil disorder.

Issue is lysosomes, so large vesicles seen in neutrophils which have reduced function. Associated with albinism, developmental delay, bleeding disorder. The connection is that all have granules, and the defect is in way that endoplasmic reticulum sorts different products into different granules.

Griscelli syndrome is similar, associated with albinism but not developmental delay or bleeding. Can predispose to haemophagocytic syndrome. Differentiate from Chediak Higashi by light microscopy of hair (unevenly distributed large melanin granules cf evenly distributed; white under polarized light cf polychromatic).

Hermansky Pudlak II has the albinism, developmental delay and bleeding, but has pigmented macrophages instead of funny neutrophils. The neutrophil numbers as well as function are reduced, whereas other subtypes do not have any immunodeficiency. Check bleeding time.

Leucocyte adhesion disorders

General paediatrics, Immunology

So white cells migrate, but don’t adhere so can’t function.

3 types:

  • Type 1= beta2 integrin defect (no adhesion)
  • Type 2=selectin ligand (a fucose transporter; no rolling). Developmental delay and hepatosplenomegaly.
  • Type 3= RAP1. Bleeding disorder can be seen too.

Classically delayed cord separation (but actually seen in any neutrophil disorder), skin ulcers esp perianal, periodontitis, raised white cell count (because they are stimulated but don’t move about normally).

Lymphocyte subsets may reveal low CD 11/18.

Irish Setters particularly prone to… Puppies rarely survive 6 months.

Chemotaxis (migration) disorders, interestingly, tend to produce pretty mild disease eg periodontitis only…

Harmful parent child interactions

Child protection

Emotional abuse and neglect – There is an obligation on a Local Authority to prove their case. This is important both for allegations made against a parent and for assessing the capacity of a parent to look after the child. In some cases the allegations against a parent are unsubstantiated or not proven in any other context when that decision is taken by Social Work.

The Supreme Court decision In the matter of EV (A Child) (No 2) (Scotland) puts the emphasis on meeting the threshold test- a risk of serious detriment is not sufficient in itself. The Local Authority must prove its case. Crucially the Local Authority must address the three following issues through explanation and evidence:

  1. What is the detriment to the child in staying in the care of his or her parents?
  2. Why is this detriment considered serious?
  3. Why is this detriment considered likely?

Potentially more delays in system while evidence is gathered.

The message from the Supreme Court is clear that the onus is not on a parent to show they have the necessary parenting skills to parent the child, but rather for the Local Authority to assess and prove they do not have the capacity to parent the child.

Central serous chorioretinopathy

Allergy, General paediatrics, Surgical

Central serous chorioretinopathy (CSCR) = accumulation of subretinal fluid at the posterior pole of the fundus, ultimately leading to retinal detachment. Typically affects one eye only.  Vision becomes blurry and distorted, with objects often appearing smaller in the affected eye. May also cause difficulty with bright lights and contrast sensitivity.

Mechanism unknown, but associated with use of systemic corticosteroids, pregnancy, and Cushing’s syndrome.  Recently also been described after local corticosteroids including inhaled, intranasal, topical and periocular (!). Rare though.

Although blurred vision is a symptom of CSCR, it can be a side effect of periocular steroid treatment, as well as a symptom of whatever underlying eye condition is present (if any).

MHRA therefore says you should inform patients they should report any vision problems or disturbances.

[MHRA]

Webcam clinics

Patients,

Webcam clinics for diabetes (Newham, all ages) – mean duration only 9 minutes for both consultants and nurses, cf 25/30 minutes for face to face!  DNA rate 13% cf 28% for face to face.

Patients felt HCPs more focussed on them, other studies have confirmed that eye contact is better! But feels more impersonal, so prior relationship is important.

Trichotillomania

Clinical, General paediatrics, OPD

Or repetitive hair pulling.  Previously classified as an impulse control disorder, ie a sense of tension that is only “satisfied” when hair is pulled out. However, many children do not get this tension and gratification so in DSM-V trichotillomania is included among obsessive-compulsive and related disorders.

Dutch cohort mostly girls, literature says no gender difference!   Nail biting can co-exist, as can stereotypies.  Many kids will also eat their hair once it is pulled out.  Most common age of onset is in early adolescence (9-13 years), but frequently occurs in early childhood, even as early as 12 months of age.  Triggering factors identified include concerns about physical appearance, family and school issues, and concurrent illness.  Parents sometimes also pull their hair, so maybe (partly) learned.

Two distinct types of trichotillomania described: automatic and focused

  • Automatic – outside of own awareness, may not recall actual pulling, but may admit to ‘playing with their hair’ or may have been noted to pull their hair in a distracted state.  Children tend to fall into this category.
  • Focused – aware, in response to negative emotion or urges

Parents often miss the hair pulling and only present when hair clumps noticed on surfaces (esp bed –  presumably due to pulling in sleep) or bald patches appear.

On Examination

Exclamation mark hairs (thin proximally, at scalp, normal distally), usually thought of being evidence of alopecia areata, may be seen, so not very predictive.  Pull test – gentle traction on about 20 hairs in 3 different locations.  Positive if more than 5 hairs extracted – suggests active alopecia areata.  You may miss dormant alopecia, but in that case hair regrowth should occur.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4857813/]

Anaesthetic allergy

Allergy, General paediatrics, Immunology

Reactions to local anaesthetics are often reported, but given how often they are used, most turn out not to be allergic but rather toxic (eg to parabens or sulphite preservative) or autonomic. Where allergy is confirmed, it is often of a delayed hypersensitivity type eg 24-72 hours after exposure. Beware latex allergy and C1 esterase inhibitor deficiency too. Local anaesthetics come in 2 main groups, the esters (procaine, benzocaine) and the amides (lidocaine, bupivocaine). Cross-reactivity is common among the esters but not among the amides or between the 2 groups. Neomycin sensitivity may contribute to a reaction.

Asthma prevention

Common, General paediatrics, Respiratory

Atopy is not a single phenotype, the idea of an “atopic march” from infantile eczema through food allergy to asthma and rhinitis is way too simplistic. Early interventions have been disappointing. Curiously, food allergies and eczema often improve through childhood – this seems less common with asthma.

There are different risk groups.  Environmental exposure to allergens and microbes in early life is one factor.  Farm environment protects (exposures and/or dietary).

Most studies show dog ownership protective. Weaker evidence for cats. House dust mite sensitisation in early life predicts asthma in school age.  Primary prevention of HDM sensitisation has conflicting evidence – Isle of Wight study showed mite avoidance prevented sensitisation and asthma; Canada study showed effectiveness but Dutch study did not.  Manchester study reduced early wheezing but had higher rates of sensitisation. Australian study no effect overall but depended on age.

Reduced bacterial diversity is a risk factor for asthma and atopic wheeze – certain bacteria esp bacteroides and firmacutes seem to be protective.

Viruses also play a role.  RSV is associated with later asthma regardless of existing atopy or not, although perhaps not with asthma persisting into adulthood; rhinovirus wheezing in first 3yrs is similarly associated with persistent wheeze, especially in atopic persons. So impact of more RSV and other vaccines could be fascinating.

Heritability of asthma accounts for less than 50% of patients so gene-environment interactions are at least as important.  A gene has been found that is associated with early childhood asthma with severe exacerbations (CDHR3). TSLP gene on chromosome 5q22 encodes for a master regulator for TH2 processes. But another well recognised gene region on chromosome 17q12-21 (including ORMDL3 and GSDMB) seems to be involved in airway dysregulation after virus infection, rather than allergy.

Increasing evidence that respiratory health is influenced by parental exposures that occur long before conception. The strongest evidence relates adolescent tobacco smoking and overweight in future fathers to increased asthma and lower lung function in their offspring, supported by evidence on parental preconception occupational exposures and air pollution.  Antenatal and postnatal (passive) smoking important. Role of breast feeding vs formula still controversial.

No evidence for asthma preventer treatment as an early intervention – cf JIA and other inflammatory conditions.

Grass immunotherapy for rhinitis in children reduces the incidence of later asthma and need for asthma medication. Presumably house dust mite immunotherapy would help too? HDM antigens have allergenic but also endotoxin and enzymatic effects! Jurgen’s study of HDM SLIT in infancy found reduced sensitisation (to anything, but def HDM – but only 11% difference and active group had more pets…); at 3 yrs, no difference in clinical outcomes, unfortunately – in fact, more wheeze…

Spanish RCT of oral bacterial extracts (6 different ones for 6 months) significantly reduced number of wheeze episodes (40%) for up to 1 year. Animal experiments have already shown that oral administration of bacterial extracts prevents bronchial hyperreactivity.

We should therefore encourage less Caesarean sections, more breast feeding, less antibiotic use, more green spaces, more “natural” food preparation and distribution (ie less plastic!).

[PAI 2023]

Toxic shock syndrome

General paediatrics, Infectious disease

Criteria for Staphylococcal Toxic Shock Syndrome (TSS)

Necrotizing fasciitis

General paediatrics, Infectious disease

Life threatening infective necrosis of superficial tissue fascia, often more extensive than would be suspected by appearance of overlying skin.  Can start in previously normal skin, with an insignificant entry site!

Group A streptococcus mostly, but can be polymicrobial especially in immunocompromised.

The top three early presenting clinical features are swelling, pain and erythema but these are entirely non-specific, so initial misdiagnosis common (almost three-quarters of patients in 1 review). More specific features are:

  • pain out of proportion to the physical findings;
  • failure to improve despite broad-spectrum antibiotics;
  • presence of bullae in the skin; and gas in the soft tissue on plain X-ray.

Other possible characteristics described:

  • tense oedema extending beyond margin of erythema
  • loss of sensation
  • LRINEC score in adults based on lab criteria (high glucose, high creatinine, high CRP, high WCC, low sodium, low Hb) has 76% sensitivity, NPV 88.1%.

Early surgical exploration is the best approach in the uncertain case; and early surgical debridement is key to control. IVIG may be of benefit.

Notifiable in Scotland.