Category Archives: Dermatology

Seborrhoeic dermatitis

Dermatology, General paediatrics

Scaly skin condition in babies, particularly affecting scalp. Red/orange scales, oily, flaky.  Not terribly itchy.

Affects sebaceous (greasy) zones – face, scalp, centre of chest, skin folds (neck, groin).  Often nappy rash. V common (includes dandruff!).  Inside, outside and around ears can be affected.  Eyelids can be affected (blepharitis).

Babies get transient type – cradle cap (scalp) and nappy area, clears after a few months.  In adults, affects face (esp around nose and ears) and can affect chest and upper back. Can lead to hair loss but more usually cosmetic concerns.

Thought to be caused by overgrowth of Malassezia yeast.  Can be severe in HIV.

Differential is psoriasis.  Scales in psoriasis are thicker and whiter – unusual for face to be affected.

Treatment

For cradle cap in babies, usually enough just to use daily mild shampoo and gentle brushing.  Shampoo may make it worse if the diagnosis is actually atopic dermatitis!  Failing that, coconut oil (NOT olive oil, which has potential to damage skin, apparently) or other moisturizer left in overnight or applied just before bath.

For scalp, Zinc pyrithione, selenium or ketoconazole shampoo (but only licensed for older children).  Leave 5-10 mins before rinsing.  Descaling treatment available – coconut oil and salicylic acid, needs hours.

For body, moisturizer, topical steroids+antifungal eg Canesten HC, Trimovate.

For blepharitis, use baby shampoo to lift flakes.

In adults, anti -androgens.

Mastocytosis

Dermatology, General paediatrics

Proliferation of mast cells.  Can be restricted to skin or be systemic, with infiltration of bone marrow, spleen, liver and lymph nodes.  Systemic involvement not always obvious in the skin! Messy though, since mast cell mediators might act systemically even if mast cells themselves not widespread.

Systemic mastocytosis can present with episodic symptoms of dyspnoea, collapse (hypotension), reflux, diarrhoea.  Rather non-specific, so easily missed.  May also have hepatosplenomegaly, lymphadenopathy, osteoporosis, bone abnormalities.

Skin lesions may be present but not always dramatic (might just look like freckles).  May be history of dermatographism, recurrent itching, flushing and/or urticaria.  Different skin patterns seen, but overlapping:

  • mastocytoma – slightly raised, can be slightly pigmented.  Physical irritation eg scratching causes flare and weal (Darier’s sign).  Can be present at birth, tend to be a good size eg 2-4cm nodule, may be blistering (in first 2 years of life only), else appear in first year of life.
  • Urticaria Pigmentosa – usually presents in first 2 years of life, freckles or larger nodules/papules/plaques.  Can be blistering.  Resolves if not improves at puberty.
  • Diffuse cutaneous mastocytosis (DCM) – no distinct lesions visible! Serious.
  • Telangiectasia macularis eruptiva perstans (TMEP) –  brownish small macules with telangiectasia, generally in adults.  Can be systemic.

So look at skin, try Darier’s sign (not v sensitive).  Feel for liver and spleen.  Check Tryptase level (rarely normal even in systemic – compare baseline to peak, rather than just absolute level). Consider bone marrow biopsy to look for mast cells. Consider bone scan to look for abnormalities.  PCR for the D816V mutation in KIT gene?

Management

Control triggers (very individual):

  • Stress (emotional/physical), sleep deprivation, pain
  • Physical stimuation eg heat/cold, exercise/sex, sunlight, skin/scalp friction or trauma (tickling!)
  • Bee/wasp stings
  • Drugs esp aspirin/NSAIDs, opiates
  • Alcohol

60% of kids resolve during puberty!

In later life there is a slightly higher risk of haematological disorders including cancer. There is also an increased risk of osteoporosis.

Stabilize mast cells:

  • Anti-histamines, including H2 blockers.  Titrate dose to effect.
  • Cromoglycate
  • PUVA offers some temporary relief

Emergency treatment: Adrenaline auto-injectors for –

  • systemic
  • previous systemic reactions
  • Extensive blistering lesions?

UK support group at www.ukmasto.org [Jess Hobart]

[Am Fam Physician. 1999 Jun 1;59(11):3047-3054.]

Haemangiomata

Clinical, Common, Dermatology, General paediatrics

2018 classification (ISVVA.org) – rather functional and lacking in poetry!

Basically benign tumours, involving blood vessels.  Seen in 12% of all infants  – more common in girls, whites, premature infants, twins and are babies born to mothers of higher maternal age!  Mostly seen in head and neck region, including the face, but can be anywhere.

Tumours distinguished from malformations.

Infantile Haemangioma

Cutaneous/mucosal haemangiomata usually develop after birth, appearing in the first 8 weeks of life.  They then develop and grow for 6-12 months, often resembling a strawberry.  Most then start to reduce and fade gradually, although it can take up to 9 years.   Often there will be complete disappearance with no cosmetic defect, but there may well be scarring, telangiectasia, or loose fibro-fatty tissue.

Can be further differentiated by depth (superficial tend to be raised and bright red, deep are generally darker red or even purple/blue, they can also be mixed) and extent/pattern (focal or segmental).

Typically they are in the skin and soft tissues, but can sometimes affect the liver or airways.  Associated with GLUT-1 positive staining on biopsy.

Congenital Haemangioma

Much less common. Present at birth and do not progress, although they may grow proportionally with child.  Oval or round, plaques or exophytic.  Some rapidly involute during the first year of life but otherwise they are permanent.

Vascular malformations

Grow slowly compared with vascular tumours.  Usually present at birth but perhaps inconspicuous until child grows.  Can involve arteries, veins, lymphatics in various combinations.

Capillary malformations most common – dilated capillaries, classic port wine stain (naevus flammeus).  Darken over time, do not regress.  Can be associated with bone or soft tissue overgrowth. Multiple can be associated with underlying AVM!

Nevus simplex is the classic “stork bite” at the nape, eyelid or forehead at birth. Lighter, regress.

Venous malformation more ill defined, bluish, easily compressible.  Multifocal tend to be autosomal dominant.  Some syndromes eg Blue rubber bleb naevus syndrome (widespread, including palms/soles).

Lympoedema and cystic hygroma are the lymphatic versions.

Others

  • Pyogenic granuloma – reaction to trauma, well demarcated, raised or even pedunculate
  • Telangiectasia eg Hereditary haemorrhagic telangiectasia (HHT)
  • Angiokeratoma – characteristic of tubersclerosis
  • PHACE syndrome (post fossa malformations, haemangiomata, arterial anomalies, cardiovascular defects, eye anomalies – but also midline defects)
  • Tufted angioma and Kaposiform haemangioendothelioma – similar histologically, but latter bruised, purpuric appearance, infiltrate into muscle/adipose tissue and associated with Kasabach-Merritt syndrome (consumptive coagulopathy).
[Seminar intervent radiol 2017][Ped dermatology 2016]

Henoch Schonlein Purpura

Common, Dermatology, General paediatrics, Immunology, OPD, Renal, Rheumatology

or HSP. Usually preschool but any age! Boys more than girls. Vasculitis, leucocytoclastic with IgA predominance. EULAR criteria 2010.

Features:

  • Urticarial rash becoming purpuric but still raised (pathognomic), predominantly on lower limbs, especially extensor surfaces incl buttocks, but sometimes trunk, rarely face (infant).  Accompanying soft tissue swelling, as seen in photo in feet.
  • Arthralgia (not migratory, cf acute rheumatic fever)
  • Abdo pain, diffuse, colicky, often severe – possible intussusception, melaena
  • Proteinuria (30+ mmol/mg albumin:creatinine ratio), 2+ red cells on dip or 5+ on microscopy (or casts) indicating glomerulonephritis, usually asymptomatic cf streptococcal, but a few develop diffuse proliferative lesions with irreversible renal damage.
  • Scrotal rash/bruising common, rarely torsion
  • Rarely encephalitis, seizures, pulmonary haemorrhage

Pathology

Leukocytoclastic vasculitis with glomerular mesangial IgA deposits.  Biopsy of patients with IgA nephropathy identical, and indeed both groups have defective IgA1 glycosylation, which may explain why they may aggregate and precipitate IgA in small vessel walls as well as in the glomerular mesangium.

Complications

Complications and relapse associated with age esp over 6yr. 50% relapse, usually within 6 weeks but can be up to a year later; 50% of those will relapse more than once. Treat with NSAIDs (unless renal involvement!) for joint pain, analgesics for abdo pain. Small study from Turkey found that Ranitidine reduced symptoms.

Steroids (prednisolone 1-2 mg/kg/day for 1-2 weeks) are suggested (grade 2 recommendation) within 3 days of onset of severe abdominal pain (defined as pain requiring hospital admission) or acute GI bleeding – after exclusion of intussusception, of course.

Steroids are also suggested for orchitis, after excluding torsion.

Reviewing 101 children with abdo involvement those who did not receive steroids had an average of 5 days of abdominal pain, whereas all those treated recovered within 24 to 48 hours of starting steroids (letter, J Pediatr Gastroenterol Nutr. 31(3):323-4, 2000).

Abdominal pain is a predictor of renal involvement, so maybe that’s the best reason for giving steroids… (Kidney Int 1998; 53:1755-9).

Renal disease

20 to 90% risk of renal disease, but generally mild (mostly just mild proteinuria and/or haematuria)! Normal urinalysis at day 7 has 97% negative predictive value for chronic renal disease [PLoS One 2012;7:e29512].

About 56% of those children with renal disease develop signs and symptoms of renal disease a week or more after presentation, although generally in first month.  Can be up to 6 months later.  Incidence of renal failure in HSP nephritis is just 2 to 5%.  Risk factors are severe abdominal pain (OR=2.1), age >8yrs (OR=2.7), and relapsed HSP (OR=3).[Arch Dis Child. 2010 Nov;95(11):877-82. doi: 10.1136/adc.2009.182394]

A normal urinalysisNB Children who appear to recover may have significant renal disease many years later. (Lancet. 339:280282, 1992).

If more than 50% crescents on biopsy, then poor prognosis.  Only 1% get that far.

Archimedes in 2012 found 3 RCTs of steroids, treatment courses 2-4 weeks, seemed to shorten duration of abdominal pain, with most obvious effect when used early.

Dudley trial of early steroids (day 7) failed to find any benefit at 12 months (n=352).  Quite a high proportion of drop outs unfortunately, but prob not enough to influence results.  Doesn’t answer question of what to do if severe disease at onset eg nephrotic range.  [Arch Dis Child. 2013 Oct;98(10):756-63.]

Non-randomized prospective clinical trial of 223 kids showed that steroids were effective in reducing the severity of abdominal and joint pain and in treating renal disease – steroids did not prevent the development of nephritis [Archives of disease in childhood. 2010;95:877–82, doi: 10.1136/adc.2009.182394 ].  Previous systematic review suggested that steroid treatment at diagnosis did not reduce the median time to resolution of abdominal pain but did significantly reduce the mean resolution time, and increased the odds of resolution within 24 hours.

There is no proven benefit of corticosteroids in the treatment of established HSP nephritis (2009 Zaffanello systematic review, evidence is poor), but used anyway.

The major risks of corticosteroid treatment in children with HSP are masking an acute abdomen or intussuception, and GI bleeding.

Follow up

UK Kidney association guideline 2022 – for uncomplicated presentation, do frequent dipstick checks, for example weekly for first 4-6 weeks then monthly. BP check at presentation and then if evidence of nephritis. No need for parents to check at home otherwise. 6 months minimum (audit criteria, rather than recommendation).

If hypertensive or urinalysis pos, then do proper urine protein:creatinine ratio, U&Es, MC&S. Isolated haematuria is benign. As soon as urinalysis becomes normal, child can have routine follow up.

Scottish guideline was that persisting proteinuria of + or more needs more frequent follow up eg 2 weekly, 2 monthly then 3 monthly with the second line investigations.

Refer urgently for confirmed hypertension, or nephrotic range proteinuria (P:CR over 200mg/mmol).

Refer for biopsy if persisting severe proteinuria (UP: UC >250 mg/mmol for up to 4
weeks), persisting moderate proteinuria (UP: UC 100–250 mg/mmol for 3 months),
AKI stage 1 or greater (creatinine >1.5 × previous baseline or >1.5 × upper limit of normal for age). Treatment depends on histology and severity of clinical features.

ACE inhibitor is suggested (grade 2 recommendation) for persisting mild/moderate proteinuria.

A systematic review found no risk of long-term renal impairment in children with Henoch-Schonlein purpura with normal or minimal urinary findings without nephritic or nephrotic syndrome or renal failure (Arch Dis Child 2005;90:916-20). If urine analysis is normal at presentation, then test for 6 months after the last symptoms. If there is renal disease at presentation, then the risk for progression seems to be more associated with rising proteinuria during follow-up rather than presentation features. (Am J Kidney Dis 2006;47:993-1003)

Plantar warts

Common, Dermatology, General paediatrics

2/3 resolve within 2 years.  In young children, higher spontaneous clearance.  In systematic review, only salicylic acid and aggressive cryotherapy seem to be effective.  Both are user dependent.  In RCT between the 2 and conservative management, no difference detectable after 13 weeks.  So watch and wait, unless causing a lot of pain.

Perianal warts can be transmitted vertically from mother at birth, or potentially from carers changing nappies.

Warticon cream is podophyllotoxin. Else Condyline paint.

Eczema

Dermatology, General paediatrics, Immunology,

NICE (CG57, 2007) diagnostic criteria:  itchy skin plus 3+ :

  • visible flexural dermatitis (or visible dermatitis on the cheeks and/or extensor areas in children <18/12) – can look like dirt where darkened esp neck
  • personal history of flexural dermatitis (or dermatitis on the cheeks and/or extensor areas in children  <18/12)
  • personal history of dry skin (xerosis) in the last 12 months
  • personal history of asthma or allergic rhinitis (or history of atopic disease in a first-degree relative of children aged <4yr)
  • onset of signs and symptoms under the age of 2 years (do not use this criterion in children under 4 years).

On examination, may also see lichenification (increased skin markings due to chronic rubbing), excoriations caused by scratching, and hyperlinear palms (look at thenar eminence).

Risk factors

Eczema (or atopic dermatitis, same thing) associated with parental allergies (OR 1.94), parent-reported infection after birth (OR 1.45), parent-reported jaundice (OR 1.27). Being a migrant (OR 0.63) and keeping a dog (OR 0.78) are protective. Prenatal probiotics did not reduce risk (Lactobacillus rhamnosus GG, LGG).  Respiratory viral infections in pregnancy associated with wheezing illness in infants (mothers with asthma) and eczema.  [Australia, Ped All Imm 2014:25:151].  Febrile and gynae infections in pregnancy associated with eczema in child (Italy, Ped All Imm 2014:25:159].  Children of Japanese mothers with higher anxiety scores during pregnancy were more likely to be affected by eczema!

Immunology

Many roads lead to Rome!  Can be seen as combination of impaired innate and distorted adaptive immunity, interacting in framework of cutaneous immune system with suboptimal barrier function.  Epidermal barrier can be genetically disturbed, but gene expression (eg of filaggrin) is also influenced by microenvironment eg Th2 cells.  Some genetic structural abnormalities can be seen to induce nonspecific inflammatory reaction (eg SPINK5 defects).  And almost certainly, epigenetic regulation will affect gene expression in both keratinocytes and immune cells.

Facilitated antigen presentation mediated by IgE bound to high affinity IgE receptor FcEpsilonRI, on dendritic cells, is an important part of it.  Vitamin D plays a key roll, stimulates Toll like receptors, increasing pro-inflammatory cytokines but studies equivocal whether low (or indeed high) levels increase risk.

Eczema can exist without IgE against aeroallergens and food allergens, so is primarily a non IgE mediated disease, although both IgE and non-IgE hypersensitivity can co-exist, particularly in babies.

Still not understood how eczema and Staph aureus interact.  Colonization appears to amplify local inflammatory reaction, but also increases IgE against a large spectrum of other things (possibly including self proteins).  It is as if there is something specifically different about how immune cells handle Staph.  Toll like receptors esp TLR-2 recognize Staph aureus cell wall. Overgrowth of staph during flares is associated (preceded?) by loss of diversity of skin microbiome.

Unmasking of the HSV entry receptor Nectin-1 in adherence junctions, among other things, contribute to eczema herpeticum.  See Flares, below.

Atopy patch test (using intact protein allergens) can prove type IV reactions. Correlates with oral food challenge. Hyper IgE syndromes are important differential for AD, STAT3 mutations, skin (and other) abscesses, recurrent pneumonia (and pneumatocoele), connective tissue and skeletal abnormalities, mucocutaneous candidiasis. DOCK8 type Hyper IgE syndrome show sensitization predominantly against food allergens, which is a clue (STAT3 and AD show predominantly sensitization to aeroallergens).

Normal looking  skin is not immunobiologically normal!  Invisible inflammation, hence still needs treatment. Pimecrolimus and betamethasone both normalize expression of filaggrin, the later is perhaps a better anti-inflammatory but steroids reduce expression of enzymes for lipid and protein synthesis, so may impair skin barrier restoration.

Triggers

Stress, humidity, extremes of temperature can cause flares of atopic eczema. But what causes a flare in some can apparently help in others! Any factors causing flares should be avoided where possible.

UVB causes sunburn.  UVA (longer wavelength) more relevant to photosensitivity reactions.  Both cause long term skin damage.  EU commission recommends UVA protection making up at least 1/3 of total suncream SPF.  A few available on prescription for photodermatosis (incl vitiligo) but not for eczema per se.  Lipscreen (Uvistat) available for chronic/rec HSV labialis.  Sunsense is lotion.

Avoid wool in contact with skin.  No evidence that bio detergent or fabric softener a major problem.  Avoiding excessive product and not overloading machine (so disperses fully) prob more important.

Management

See eczema management.

Parental support

National eczema society, British Association of Dermatologists, Eczema Outreach Scotland.

Food additives and allergy

Allergy, Dermatology, Immunology

Sorbic acid used as preservative.  Very low level of toxicity, as rapidly metabolized (a fatty acid).  A few reports of contact dermatitis and pseudo-allergy only.

Similarly with Tartrazine, MSG, Benzoate – in most children, there is very limited evidence for any role of food additives in causing non-allergic food hypersensitivity. Reactions may be more common in children with chronic urticaria and angioedema.  While other symptoms including migraine, gastrointestinal disturbances and arthralgia have been attributed to food additives, there are no reproducible and consistent data from DBPC studies to support this.

Natural additives eg Annatto can also cause problems in some patients!

Sulphites (sulfites, eg sodium metabisulfite) and natural salicylates may cause skin (usually contact dermatitis, but can be angioedema), GI, respiratory problems (even anaphylaxis) but these are best termed adverse reactions as they have a pharmacological basis.  Patch and IgE test available, however.  Very common in our food – in fresh foods to control browning, soft drinks, dried foods (as preservative), wine and beer.  Yet very rare in childhood and therefore hard to spot.  Also seen in in anaesthetic solutions, antibiotics, adrenaline (!!!), cosmetics.  Sulphites can have effects when used topically, orally or parenterally – mostly seen in those with asthma.  Can be acute or chronic.  Given the problem with using adrenaline, may need to be treated with steroids, antihistamines, bronchodilators instead! [Clinical & Experimental Allergy. 39(11):1643-51, 2009 PMID 19775253]  

Salicylates are a large group of assorted foods and other things that can cause problems including anaphylaxis.  Natural salicylates are generally acetylated so no need to automatically avoid them if intolerance to aspirin/NSAIDs.

[PJ Turner, J Paeds Child health 2010]

Erythema multiforme

Dermatology, Immunology

Consists of well-circumscribed target-like lesions most commonly on the extremities. In about half of cases the cause is never found. Causes include:

Stevens Johnson Syndrome and Toxic Epidermal Necrolysis

Dermatology, General paediatrics, Immunology

Closely related. Characteristically severe, diffuse mucocutaneous eruption with atypical flat target lesions, irregular, possibly purpuric, blistering, even haemorrhagic! Painful, like sunburn.  Different pathology from Erythema multiforme! Evolve over 1-2 weeks, subside over further 2-3 weeks.

Other manifestations are fever (prodromal illness can manifest as URTI).  Mucosal lesions (stomatitis, conjunctivitis/blepharitis, or genital inflammation) accompanied by at least 1 other visceral organ, such as hepatic, renal, trach/bronchial or gastrointestinal involvement. Urethral involvement can cause retention of urine. Chest and abdominal signs pretty common!

Urgent ophthalmology – uveitis can lead to blindness.