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Scabies

Dermatology, General paediatrics

Serpiginous burrows between the fingers, in the flexures of the wrist, genitalia etc characteristic but rare. More usually papules, pustules – pruritus often on unaffected skin and esp at night. In infants, lesions on head, nappy area, occ palms and soles.

Caused by the mite sarcoptes scabiei, which does not fly or jump – direct skin contact, mostly. Infection by contact with fomites is very rare.

Rash is partly hypersensitivty so not related to number of mites, may take several weeks after inital infestation to appear – on reinfection just a few days. Cross reaction with related house dust mite.

Topical steroids will mask rash/itch. Superinfection common. Differential is contact dermatitis, animal scabies (do not form burrows, do not complete life cycle so self limited), lichen planus.

Rarely, nodular form (esp groin, axillae) – hypersensivity reaction. 

Norwegian or crusted scabies esp immunosuppressed (but not necessarily) – psoriaform, not always itchy, very infectious.

Treat with Permethrin 5% (=Lyclear) dermal cream [Permethrin 1% rinse cream ineffective in scabies cf head lice]. Safe in infants (rarely CNS side effects). An alternative treatment is Malathion (safe in pregnancy). All household members should be treated simultaneously. After treatment the itching from scabies can take weeks to settle. Treatment should be extended to the scalp, neck, face and ears in children up to the age of 2 years. All skin surfaces should have the agent applied for 24 hours for malathion and for 8-12 hours for Permethrin 5% and have treatment repeated at 7 days.

Oral ivermectin in single dose is effective in over 70%, given twice 2 weeks apart 95% effective. Use for crusted (along with keratolytics), epidemics. Lancet Infectious Diseases Volume 6, Number 12, December 2006

HACEK organisms

Cardiology, General paediatrics, Microbiology, Orthopaedic

Group of similar gram negative, low pathogenicity organisms – not actually related to each other, but cause similar infections:

  • Haemophilus (usually parainfluenzae, not H. influenzae which rarely causes endocarditis)
  • Aggregatibacter actinomycetemcomitans (prev Actinobacillus)
  • Cardiobacterium hominis
  • Eikenella corrodens
  • Kingella kingae

Commensals of the mouth – usually just cause dental infections but can cause endocarditis (gram positives are the usual cause) and osteomyelitis (esp Kingella – named after Elizabeth King – can be spread by respiratory route, so outbreaks of septic arthritis!).

May grow on chocolate agar but not the McConkey you usually use for gram negatives. Some beta-lactamase but most susceptible to cefalosporins.

Cowden syndrome

General paediatrics, Genetics

Autosomal dominant, PTEN gene (10q23). See OMIM.

Clinically –

  • Macrocephaly
  • Skin lesions – esp hamartomatous. Eg trichilemmomas (smooth, skin coloured, warty or dome like lesions, esp face), acral keratoses (ie on hands), papillomatous papules)
  • Increased risk for the development of breast, thyroid, and endometrial carcinoma

In some cases intestinal polyps, papilloedema, immunodeficiency.

LTP allergy

Allergy, General paediatrics

Lipid transfer protein. One of the allergen families. Cross reactions therefore seen with fruit (stoned fruit but also raspberry), nuts, seeds (eg linseed/flaxseed), pulses, even cereals, tomatoes, vegetables (lettuce! Cabbage!). You may also see reactions only to composite foods eg pizza, curry, due to multiple allergens being present, but only producing reaction due to co-factors.

A less common cause of Pollen food syndrome than PR10 allergy. Thought of as a Mediterranean thing but increasing reports from Northern and Western Europe. Plane tree and mugwort have LTP but not thought to be the usual cause for sensitisation (except maybe in China). In N/W Europe, often birch sensitised too but not to be confused with PR10 type PFS!

Important to identify because heat stable (so not affected by heat, processing, digestion etc in the way PR10 allergens are) and potential for severe reactions.

So do component testing if atypical (eg unusually severe) reactions to fruit.

LTP allergy also seems to be more likely to cause reactions of varying severity, compared with primary food allergy, with co-factors perhaps more important. Eating multiple different plant foods at the same time seems to be the most likely cause of co-factor associated severe reactions. Of course, co-factors can co-exist too (alcohol and dancing, for example). So some would advise:

  • Avoid exercise for 2 hours before (more in same cases) and 4 hours after eating
  • Avoid NSAIDs for 2 hours before and 2 hours after
  • Avoid alcohol with food or after
  • Eat cautiously if not had for many months
  • (sleep deprivation, cannabis, stress, fasting, anti-reflux medication…)

Diagnosis

Danger that with LTP allergy you show sensitisation to multiple foods, and then you end up on a restricted diet without knowing whether there is allergy or not.

Peach allergen Pru p 3 is a good surrogate for LTP allergy, even if peach hasn’t been a problem! If not available, you could test with SPT reagent for peach that is rich in pru p 3 (but might be false positive due to other components being present. London plane and mugwort allergy would also support.

Wheat is a bit tricky – the wheat LTP Tri a 14 is only 45% homologous with Pru p 3 so may get missed. Given the co-factor issue, probably good to do Tri a 19 (omega 5 gliadin, as in exercise induced anaphylaxis) as well.

Where hay fever and atypical reactions to nuts, do the LTPs Ara h 9 (peanut), Cor a 8 (hazelnut), Jug r 3 (walnut). You would do the other components to exclude primary food allergy which can co-exist with LTP sensitisation.

Food challenges have limited use in this situation – if positive, unclear whether LTP is the cause, and if negative, perhaps because of co-factor issue! Exercise challenge?? May just need a bigger dose!

Management

Individualize, to balance risk of reaction against dietary restriction.

Safest fruit/veg appear to be potato, carrot/root vegetables, beans, peas, melon, cashew and pistachio. Avoid pips and skin. Banana is hit and miss.

Good results with Pru p 3 sublingual and oral peach juice immunotherapy in Spain and Portugal.

McCulloch case

Communication, Ethics, Generic, Patients

Clarifies an aspect of the Montgomery decision in a way that supports healthcare professionals getting consent. The decision can be found here.

In Montgomery, the Supreme Court said that a doctor ‘is under a duty to take reasonable care to ensure that the patient is aware of any material risks involved in any recommended treatment and of any reasonable alternative or variant treatments’. In the McCulloch case, the Supreme Court was asked to decide what legal test was applicable when assessing whether an alternative treatment was ‘reasonable’. Was it the Montgomery test or was it the Hunter –v- Hanley test? Put another way, was the decision about whether to discuss an alternative treatment with a patient one of clinical judgement, or was it one for the Court to assess and determine?

The decision was that a doctor (or other healthcare professional) who has decided that a treatment is not a ‘reasonable alternative treatment’ for a particular patient will not be negligent in failing to inform the patient of that alternative treatment if the doctor’s view is supported by a responsible body of medical opinion. In other words, this decision involves an exercise of clinical judgement and any challenge to that decision by a patient is therefore to be determined by the Hunter –v- Hanley test. In the circumstances of the McCulloch case, the application of that legal test resulted in the claim being rejected by the Court.

The court said this:

“Taking a hypothetical example – say that there are ten possible treatment options; the doctor, exercising his or her clinical judgment, decides that only four of them are reasonable and that decision to rule out six is supported by a responsible body of medical opinion. The doctor is not negligent by failing to inform the patient about the other six even though they are possible alternative treatments.

“The narrowing down from possible alternative treatments to reasonable alternative treatments is an exercise of clinical judgment to which the professional practice test should be applied. The duty of reasonable care would then require the doctor to inform the patient not only of the treatment option that the doctor is recommending but also of the other three reasonable alternative treatment options (plus no treatment if that is a reasonable alternative option) indicating their respective advantages and disadvantages and the material risks involved in each treatment option.”

[Michael Stewart, Central Legal Office]

Monkeypox

General paediatrics, Infectious disease

=mpox (considered less stigmatising?).

Emerging infection particularly in men who have sex with men. Reached the UK in 2022.

New variant (Clade I) has high mortality, started in Central Africa (Congo, Central African Republic, Burundi, Uganda), now in Kenya, first case now reported in Europe (Sweden, 2024). Grade 3 human pathogen (along with Yersinia pestis, O157, TB, anthrax…).

Viral haemorrhagic fever found in these areas too, of course…

Incubation period is 5-21 days. High risk would be household contact, mucosal (with bodily fluids) or broken skin, inhalation without PPE if cleaning room or changing bedding. Medium risk would be intact skin with bodily fluids or face to face within 1m considered medium risk – do not need to isolate but should be offered post-exposure prophylaxis. See PHS matrix.

Besides blistering rash, can cause fever, sore throat, lymphadenopathy, myalgia.

Swab blistering lesion, or if none then throat. MSS (molecular sampling solution, as used for flu etc) ideally otherwise extra transport precautions required. Mark sample “suspected HCID”, notify lab in advance – needs to arrive for 9am!!!

Cases are asked to self isolate at home.

PPE – as for viral haemorrhagic fever. https://learn.nes.nhs.scot/58193/high-consequence-infectious-diseases-hcid

Post-exposure prophylaxis with MVA-BN vaccine (Imvanex®) offered within 14 days. Pregnant and children under 5 considered at risk.

Smallpox vaccine was considered effective.

Mental health emergency

Child protection, Common, Emergency medicine, General paediatrics, Mental health

Firstly, is there a suicide risk?

Then, consider mental health needs. Is there an alcohol or drug issue?

Are they known to social work? Are there any child protection issues for the young person? Their siblings or other family members? If young person is over 16 then consider Adult Protection measures (Scotland Act 2007).

A proper mental health assessment requires that they are physically well enough (consider intoxication, sedation, pain etc). Consider competency (which can be impaired temporarily by physical illness).

Consider:

  • Violent/aggressive behaviour – needs risk assessment and management
  • Evidence of learning disability
  • Any existing care plans or coping mechanisms?
  • Psychosis? ie delusions, hallucinations
  • Unusually withdrawn/quiet is a red flag.

Chronic Variable Immunodeficiency

General paediatrics, Immunology

=CVID. Another terribly named condition.

Usually presents in adulthood but about 20% in childhood. Typically recurrent infections of ears, sinuses, lungs – usual bugs, not funny ones.

Bronchiectasis may develop. In some cases granulomas develop.

Lymphadenopathy +/- splenomegaly is sometimes a feature.

Autoimmunity is an important feature – low red cells or platelets, thyroid disease.

Enteropathy and arthritis can be seen.

Diagnosis

Low IgG, usually IgA, sometimes IgM. Functional antibodies (to pneumococcus, tetanus, Hib) low.

Treatment

Immunoglobulin replacement – IVIG or subcut immunoglobulin, regularly.

Prophylactic antibiotics in some cases. Screen for infections esp chronic GI.

Bias

Ethics, Generic

In research, many studies are non-randomized, so risk of bias.

Newcastle-Ottawa scale is one attempt to assess bias formally – judged on:

  • the selection of the study groups;
  • the comparability of the groups;
  • the ascertainment of either the exposure or outcome of interest for case-control or cohort studies respectively. 

So things like cohort not being representative; control group coming from different population; measurement being rather subjective; duration of follow up – all increase risk of bias.

Publication bias

Suspicious if small study with big effect!