Rash and Skin lesions Paeds

Question 1

A 3 y/o presents with fever and corzya lasting for about 3 days with a new onset of a rash. The mother says the rash started on the head yesterday and has now spread to the body and arms. Hx reveals the mother is against vaccinations. O/E you notice the maculopapular rash and white spots surrounded by erythema in the mouth. What is the most likely Dx ad what is your management?

1. VZV
2. Erythema Infectiosum
3. Rubella
4. Measles
5. Mumps
6. Roseola Infantum
7. Hand Foot and Mouth Syndrome

Answer 1

4. Measles

The prodrome of fever and corzya including conjunctivitis 2-4 days before the onset of a rash is common in Measles. The rash is also characteristic being maculopapular, starting on the head and spreading to the trunk and extremities. The white spots surrounded by erythema in the mouth are Koplik’s Spots which can be present 1-2 days before the onset of the rash. The mother’s anti-vaxer approach also supports the Dx of Measles.

Diagnosis is mainly clinical with ELISA (IgM detection) from a blood sample or RT-PCR from a nasopharyngeal aspirate being useful in confirming the clinical suspicion

Management is supportive with Vitamin A supplements to boost antibody responses

Paces:

• Explain what measles is
• ICE about vaccinations
• Explain the importance and suggest vaccination

Complications can occur, these are:

• Neuro: Encephalitis and rarely Subacute Sclerosing Panencephalitis ~7 years later
• Eyes: Conjunctivitis
• Resp: Pneumonia and Tracheitis
• Heart: Myocarditis
• GI: Hepatitis, Appendicitis and Diarrhoea

Pathology
- Cycle of infection: Transmitted by water droplets with humans being the main host -> Infects epithelial cells of the nose and conjunctiva -> Spreads to regional lymph nodes -. Viraemia present at 2-3 days and 5-7 days -> Infects skin and upper respiratory tract at 7-11 days at which point the prodrome symptoms occur -> Rash occurs at day 14 at which point there are viruses in the skin, respiratory tract, blood and other organs -> Viraemia decreased from day 15 as antibody production increases

Question 2

A 3 y/o presents with a rash that started on his head but has now spread to his body. It got better following a hot bath but has since worsened. His mother is against the vaccination of children. O/E you notice the maculopapular rash and that the post-auricular lymph nodes are enlarged. What is your most likely Dx and what is your management?

1. VZV
2. Erythema Infectiosum
3. Rubella
4. Measles
5. Mumps
6. Roseola Infantum
7. Hand Foot and Mouth Syndrome

Answer 2

3. Rubella

The maculopaular rash is often the first sign of Rubella. Like Measles, it starts on the head and spreads to the trunk and body but is often not preceded by prodrome symptoms. The rash can be attenuated by heat. Lymphadenopathy is a common finding O/E with the post-auricular, occipital and posterior cervical nodes most likely to be affected. The anti-vaxer approach of the mum also suggests Rubella.

Ix is a predominantly a clinical one with a FBC (to exclude thrombocytopenia) and ELISA +/- PCR useful in confirming Dx.

IT IS IMPORTANT TO ASK THE MOTHER IS SHE IS VACCINATED AND POSSIBLY PREGNANT AS FOETAL INFECTION -> DEVELOPMENTAL DELAY, CATARACTS/GLAUCOMA, CONGENITAL HEART DISEASE AND IUGR

Tx = Supportive unless the mother is pregnant in which case she needs urgent referral to a specialist. Address any complications

Paces:

• Explain what measles is
• ICE about vaccinations
• Explain the importance and suggest vaccination

Complications

• Encephalitis
• Myocarditis
• Thrombocytopenia
• Arthritis

Pathology
o Transmitted in bodily fluids (typically nasopharyngeal secretions) by either touch or water droplet inhalation
 CAN ALSO BE TRANSMITTED VIA PLACENTA TO THE FOETUS
o Peak incubation period = 14 days but highly variable (2-23days)
o Virus replicates in the nasopharynx and local lymph nodes before haematogenous spread to other organs

Question 3

A 3 y/o comes in with bright red cheeks. The mother is adamant that she has not strike the child and says they had a mild fever and symptoms of Coryza a week earlier. O/E the macular rash does not extend to the nasal bridges or paranasal areas. What is your likely Dx and what is your management?

1. VZV
2. Erythema Infectiosum
3. Rubella
4. Measles
5. Mumps
6. Roseola Infantum
7. Hand Foot and Mouth Syndrome

Answer 3

2. Erythema Infectiosum

The slapped-faced appearance is classical of Erthema Infectiousum caused by Parvovirus B19. This rash spares the nasal bridges and paranasal areas. This will progress to a maculopapular rash on the trunk after 1-4 days and finally a lacy reticulated erythematous rash that will persist for 1-3 weeks.

Management

• Clinical Dx with FBC to check for cytopenia and pregnancy test for the mother.
• Management = Supportive (blood transfusion if aplastic and address immunosuppression where appropriate)

Other presentations of B19

• Asymptomatic
• Aplastic crisis if immunocompromised or reduced RBC lifespan (SCA, Thalassaemia and haemolytic anaemia)
• Hydrops Faetalis if congenital infection

Pathology
o Spread via respiratory droplets or by vertical transmission across the placenta
o Viraemia occurs at days 4-14 and ends with the production of IgM
 B19 has affinity for the P antigen on red cell precursors thus affecting immature red cells
o IgG appears ~4 days after the viraemia and is associated with the Exanthema and Myalgia

Question 4

A 3 y/o presents with a rash on the neck and trunk and a 2 day Hx of Diarrhoea. The child is up to date with their vaccinations. O/E you see a macular rash with lesion 3-5mm in diameter on the neck and trunk. In the mouth, you see red papules on the soft palate and uvula. What is your most likely Dx and what is your management?

1. VZV
2. Erythema Infectiosum
3. Rubella
4. Measles
5. Mumps
6. Roseola Infantum
7. Hand Foot and Mouth Syndrome

Answer 4

6. Roseola Infantum

Roseola Infantum is typically caused by HHV6/7 but can also be caused by Coxsackie Parainfluenza and Adenovirus. It is spread by respiratory tract secretions including kissing.

Typical presentation is of a macular rash with lesions 3-5mm in diameter that cover the trunk and neck but rarely to head. Nagayama’s spots can be seen on the soft palate and uvula. Other signs include diarrhoea, tympanic membrane inflammation and URTI like symptoms.

Complications include aseptic meningitis/encephalitis -> seizures and hepatitis

Management

• Ix is a clinical Dx based on Hx and examination although a full septic screen should be conducted if there are any signs
• Tx is symptomatic relief and supportive therapy

Question 5

A 2 y/o presents with a 2 day Hx of fever and rash which started on the head and has now spread to the trunk and extremities. You see that the child is itching this rash and that there are lesions in different stages with some crusting over and healing. O/E you see macules, papules, pustules and crusted lesions. What is the most likely Dx and what is your management?

1. VZV
2. Erythema Infectiosum
3. Rubella
4. Measles
5. Mumps
6. Roseola Infantum
7. Hand Foot and Mouth Syndrome

Answer 5

1. VZV (Chickenpox)

First infection of VZV = Chickenpox

The fever, which typically lasts <3 days, coincides with the onset of the rash. The rash goes in cycles with new lesions appearing within the first 10 days. This produces lesions of different stages seen here. The cycle is macules -> papules -> pustules -> crusted lesions. New lesions should not appear after 10 days (cellular immunity defect) nor should the fever last >3 days (superimposed bacteria infection).

Management

• Ix is clinical
• Tx is supportive only unless there are complications (aseptic meningitis, encephalitis and Cerebritis, Haemorrhaging, Pneumonitis or DIC/superimposed bacterial infection) or serious illness in which case IV Aciclovir is given

Pathology
o Spread via direct contact of skin lesions or respiratory droplets
o Initial viraemia phase following infection of local lymph nodes
o Day 4-6 of the virus is transported to the Spleen and Liver + other parts of the RES
o Transportation of the virus to the skin by mononuclear granulocytes on day 9 -> rash
 VZV causes vasculitis and epithelial cell degeneration
o Following the initial infection, the virus lays dormant in the dorsal root ganglia and cranial nerves

Re-activation of VZV = Herpes Zoster and Shingles
- This presents with unilateral dermatomal distribution of a maculopapular rash +/- pain and pruritus

Tx
 1st line = Oral antiviral (aciclovir, famciclovir or valaciclovir) + adjunct = pain relief and supportive therapy
 2nd line (if immunocompromised) = IV antivirals + adjuncts
 Refer to Ophthalmologist if infection near the eyes

Complications of shingles are the same + Ophthalmicus which is inflammation and glaucoma -> blindness due to Trigeminal nerve HZV

Question 6

A 3 y/o presents with lesions in the mouth and a fever of 37.9 that has persisted for 2/3 days. O/E you see macules, papules and pustules on the tongue, gingiva and buccal mucosa + vesicopustules with a thin wall and erthematous halo on the hands. What is the most likely Dx and what is the management?

1. VZV
2. Erythema Infectiosum
3. Rubella
4. Measles
5. Mumps
6. Roseola Infantum
7. Hand Foot and Mouth Syndrome

Answer 6

7. Hand, Foot and Mouth Syndrome

Commonly caused by enteroviruses such as Coxsackie, this causes the characteristic lesions in the oral cavity and on the feet/hands. Such lesions can also occur externally around the mouth. This is associated with a low grade fever. The lesions in the mouth typically heal within 7 days and the foot/hand lesions within 10 days.

Management

• Ix is clinical but EV71 virology shoudl be ordered if the patient has travelled to Asia or has had contact with those who have. EV71 causes severe disease
• Tx is supportive with fluids, antipyretics and analgesia but those with EV71 should be admitted

Question 7

What are the TORCH pathogens and what are their generic signs?

Answer 7

TORCH pathogens are the causes of severe/common congenital infection. They include Toxoplasmosis, Others (Mumps, HIV, Syphilis and Parvovirus B19), Rubella, CMV and Herpes Simplex (VZV)

Generic signs include:

• IUGR
• Cerebral calcification and hydrocephalus
• Sensorineural hearing loss
• Cataracts and Retnitis
• Congenital Heart defects
• Pneumonitis
• Bone deformities
• Orgaomegaly
• Cytopenia
• BLUEBERRY MUFFIN OR PETECHIAL RASH

Question 8

Describe Toxoplasmosis congenital infection?

Answer 8

• This is caused by the parasite Toxoplasmosis Gondii.
• Infection is from raw meat or the faeces of infected cats which is transmitted via the placenta during the parasitaemia phase
• Only 0.1/1000 love births are infected of which only 10 % become symptomatic
• The common signs are Cerebral calcification, hydrocephalus and retinopathy leading to delayed/impaired neurological development
• Other generic signs of TORCH pathogens can be present
• Asymptomatic individuals are at risk of developing chlororetinitis as adults

Tx = Pyrimethamine and Sulfadiazine for 1yr

Question 9

Describe congenital Mumps infection?

Answer 9

Commonly caused 1st trimester spontaneous abortions with a tenuous link to endocardial fibroelastosis (thickening of the endocardium due to excess collagen)

Question 10

Describe congenital Parvovirus B19 infection?

Answer 10

HYDROPS FAETALIS

Question 11

Describe congenital HIV infection?

Answer 11

3 routes of transmission from mother to child:

• Via placenta in uteroii
• At delivery due to sharing of blood
• Post-partum due to breastfeeding

Less commonly HIV can be spread via blood products, infected needles and sexual abuse

Presentation can vary:

• Some progress to AIDS within 1 year
• Some present in childhood/adolescence with recurrent and atypical infections
• Some are only identified following screening after other family members are diagnosed with HIV

Ix/Dx

• < 18 months maternal IgG present indicating exposure but not infection. PCR = more accurate. 2 -Ve PCRs more than 2 weeks apart in first 3 months of life indicates HIV -Ve which is confirmed after 18 months
• > 18 months = serology for detection of HIV antibodies

Preventing transmission to the foetus

• HAART for mother to reduce viral load
• Avoid PROM and Forceps if vaginal delivery
• C-section if mothers viral load is still detectable
• PEP for child

Tx

• HAART + cotrimoxazole if infant or low CD4
• Vaccinations but avoiding live attenuated vaccines
• MDT and follow-up

Question 12

Describe congenital Syphilis infection?

Answer 12

The risk to the child is minimal with good prognosis if the mother is identified and treated effectively for 1+ months before delivery. If in doubt, the child should receive Penicillin.

Characteristic presentation is with a rash on the feet and hands + bone lesions. Other generic signs are present

Question 13

Describe congenital Rubella infection?

Answer 13

• Congenital Rubella infection is most serious within the 1st 8 weeks of gestation with 80% having cataracts, deafness and Congenital Heart Disease (PDA and Pulmonary Stenosis) if infected.
• From 8-13 weeks, only about 30% experience deafness
• > 13 weeks, exposure has minimal risk unless viraemia persists following birth

Other generic signs are present

All mother sexposure to Rubella who aren’t vaccinated should be tested with those infected being urgently referred to a specialist for scanning and possible IM Ig

Question 14

Describe congenital CMV infection?

Answer 14

• 0.5-1/1000 live births affected
• mothers will typically be asymptomatic or have mild, non-specific symptoms
• 90% of children are unaffected
• 5% present neonatally, predominantly with neurological deficits/signs: Epilepsy, Cerebral palsy, hearing loss and cognitive impairment + generic signs
• 5% present in childhood with sensorineural hearing loss
• There is no vaccine or screening for CMV but Tx with Ganciclovir should be started ASAP if suspected or confirmed infection

Question 15

Describe congenital VZV infection?

Answer 15

• VZV infection <20 weeks gestation has a low risk of complications
• VZV +/- 5 days from delivery has a high mortality (30%) as the foetus is not protected by maternal Ig during this period

Question 16

A 2 month girl born prematurely to an older mother presents with a bright red rash on her face that has developed rapidly over the last few weeks. O/E you see a red papular rash that is warm to the touch and is bleeding. What is your most likely Dx and what is your manegement?

Answer 16

Haemangioma

• These are often mistaken for telangiectasia or bruises at birth but develope rapidly over the coming months. As well as bleeding, these lesions can also ulcerate
• Risk factors include: female sex, prematurity, SGA, older mothers, mother with a Hx of infertility and multiple pregnancies
• Diagnosis is mainly with a doppler USS with biopsy to confirm Dx. MRIs are also useful in determining the relationship to surrounding structures
• Asymptomatic lesions are left alone until cosmetics become an issue
• Lesions with functional impairment or immediate cosmetic issues are treated with Propanolol +/- corticosteroids with surgical excision once impairment and cosmetics concerns require intervention
• If the lesion is ulcerated, barrier protection should be used with topical Metronidazole and Becaplermin (PDGF to stimulate healing) used at the clinicians discretion

Question 17

A new-born presents with multiple small cysts on the nose and under the eyes. O/E you notice these cysts which are not inflamed and appear to be of little consequence to the child. What is your most likely Dx and what is your management?

Answer 17

These appear to be milia.

• Milia are multiple small cysts, 1-2mm in diameter, that are formed due to Keratin entrapment
• They are often not pruritic or painful but can become irritate after friction
• Dx is clinical with no intervention required in the majority of cases
• Lancing or Cryotherapy can be used

Question 18

A 7y/o presents with multiple, raised skin lesions on his abdomen. These are skin coloured, non-tender and are umbilicated. What is the most likely Dx?

Answer 18

Molloscum Contagiosum

• This is cause by the Poxvirus transmitted by person-to-person contact
• In children, this typically occurs on the trunk and extremities whereas in adults it occurs on the groin and genitalia.
• Lesions are skin coloured umbilicated papules which may be pruritic and tender
• This is a clinical Dx with no specific treatment although topical analgesia and antibacterials may be required for complications
• Cryotherapy can be used to get rid of lesions which persist

Question 19

A 1 month child is brought into the GP by their mother with what appears to be large bruises over the lower part of the spine and the buttocks. The mother is adamant that they have not hit or dropped their child. Following a discussion with the mother you believe her. What is the most likely Dx and what is your management?

Answer 19

Monogolian Blue Spot

• These lesions appear like bruises (flat, irregular blue/blue-grey lesions that are 2-8cm in diameter) and can be mistaken for signs of abuse. They are typically found over the lumbar and sacral spine but can occur on the extremities. The difference is that these lesions will persist much longer than any bruise
• These are birth marks that appear within the first 2 months of life, if not at birth caused by the failure of melanocytes to migrate into the epidermis
• There is no specific Ix or Tx but you must ensure child safe-guarding is not an issue and reassure parents

Question 20

A 3 week old presents with an erythematous rash that has since formed yellow plaques. It initially began on the scalp but has spread to behind the eyes and the forehead. The child appears to be unbothered by the rash. What is the most likely Dx and what is your management?

Answer 20

Seborrhoeic Dermatitis

SD begins with an erythematous rash which then forms an adhesive yellow plaque. These starts on the scalp but can spread to the face, behind the ears and then onto the neck, flexural regions and napkin area. The rash is not pruritic or painful so children are often unbothered.

• SD is most common in those <3 months

Managemnt

• This is a clinical Dx
• If limited to the scalp, emolients can be used to prevent the skin from cracking (older children can use champoo with salicylic acid or anti-fungals)
• Topical antifungals and steroids can be used if the SD extends beyond the scalp with oral antifungals given if there is extensive disease

Question 21

A 6 week baby presents with a bright red rash over the napkin area. O/E you notice this spares the flexural regions and is not erosive or ulcerated. What is the most likely Dx and what is your management?

Answer 21

Napkin Rash

• Napkin rash is a bright erythemtous rash of the napkin area that spares the flexural surfaces. Severe case can become infected and ulcerate.
• The most common form is irritant napkin rash due to urine. The presence of GI pathogens from faecs can increase the risk as they break down urine and increase the pH -> rash. That being said, good napkin hygiene is not always preventative.
• other causes include candida, bacterial infection, Eczema and seborrheic dermatitis

Managemnt

• You may want to swab the area for MC&S but this is largely a clinical Dx
• Tx is with good napkin hygiene and barrier protection (Zinc Oxide)
• Topical nystatin or Meconizole can be used if the rash persists >3 days
• Antibiotics and topical steroids can be used in case of infection or severe irritation

Question 22

A 1 y/o presents with a pruritic skin rash on the forehead that they have since scratch. There is a FHx of atopy. O/E you notice erythema with weeping ad scaling. What is the most likely Dx and what is your management?

Answer 22

Atopic Dermatitis/Eczema

• Eczema is common in those with a FHx of atopy
• It is rare <2 months but the majority present by 2yrs
• Affected regions are typically on the fac e and scalp in infants with flexural surfaces and areas of friction more commonly affected in older chidlren
• The lesions are initially pruritic -> scratching -> erythema, weeping and scaling
• This persists and over time the area can undergo lichenification

Management

• Clinical Dx with allergy testing +/- swab for MC&S
• 1st line = avoid irritants and use emollients
• 2nd line = topical steroids
• 3rd line = immunomodulation (Tacrolimus -> UV therapy -> Systemic [Ciclosporin->Azathioprine or Methotrexate])
• Adjunct = antibiotics (include S.Aureus cover) if infection

PACES

• Educate about causes (defective barrier function) and predisposition of irritants
• Educate about management
• Educate about red flags of infection/poor control
• 50% grow out by 12yrs and 75% by 16yrs
• ICE

Question 23

A 13 y/o girl that has recently started her periods presents with inflammed lesions on her face. O/E these pustules are quite extensive with some scarring. What is the likely Dx and what is your management?

Answer 23

Acne Vulgaris

• 4 factors contribute to Acne Vulgaris: Sebaceous gland hyperplasia and excess sebum production, Cutibacterium Acnes colonisation, abnormal keratinoctye shedding due to adhesion and inflammatory cell recruitment
• Acne typically presents around the time of puberty with erythematous papules and pustules

Management

• Clinical Dx
• 1st line = Topical Retinoid + Macrolide as there is inflammation present
• Adjuncts = Benzoyl peroxide/Azaleic acid or Oral corticosteroids in severe cases
• As she has just started her periods, the OCP can also be an option for controlling acne

Question 24

A 12 month old baby presents with a purple rash on both her legs and a bleeding nose. The mother says the baby is eating/drinking normally and is developing/growing well. They had a URTI 2 weeks prior but other than that is perfectly well. The FBC reveals thrombocytopenia and the blood film confirms this but shows no abnormal cells. What is your most likely Dx and what is your management?

1. ITP
2. NAITP
3. Purpura Fulminans
4. ALL
5. Henoch-Scholein Purpura
6. DIC
7. TTP
8. MDS

Answer 24

1. ITP

ITP is the most common cause of thrombocytopenia in children and is a Dx of exclusion.

There are the main mechanisms by which ITP arises: IgG targeting platelet antigen, antibody destruction of megakaryocytes and T-cell mediated destruction of platelets and megakaryocytes in the bone marrow.

Presentation is with petechial/purpuric rash that is typically triggered by a viral infection 1-2 weeks prior. Epistaxis and mucousal bleeding are also seen with extensive bleeding being uncommon. ICH is a rare but serious presentation. There should be no signs of infection, malignancy or bone marrow failure.

Dx is via exclusion

• FBC = thrombocytopenia
• Blood film confirms true thrombocytopenia and the absence of any abnormal cells indicating MDS or malignancy

Question 25

A newborn baby presents with petechial rash. There were no risk factors for sepsis (PROM, maternal infection, GBS, prematurity) and the baby is not haemodynamically unstable or cyanotic. The mother reported that a similar thing happened with a previous pregnancy. FBC reveals thrombocytopenia and the blood film reveals no abnormal cells. What is the most likely Dx and what is your management?

1. ITP
2. NAITP
3. Purpura Fulminans
4. ALL
5. Henoch-Scholein Purpura
6. DIC
7. TTP
8. MDS

Answer 25

2. NAITP

Neonatal autoimmune thrombocytopenia purpura occurs shortly after birth and results from IgG against Human Platelet antigen 1a crossing the placenta following sensitisation. This occurs in HPA1a -Ve mothers who have a HPA1a +Ve child.

Child presents with classical thrombocytopenia symptoms. Other causes of thrombocytopenia and petechial rash should be excluded (sepsis -> DIC, congenital bone marrow failure)

Tx is with a transfusion of HPA1a -Ve cells until the maternal Ig are cleared from the ciculation

Question 26

A 4 y/o caucasian male presents with a purple rash, abdominal pain and swollen ankles. There are no signs of infection although the child did have an URTI 1 week prior. FBC reveals thrombocytopenia and the blood film shows no abnormal cells. U&E, urine dipstick and MC&S are normal. What is your most likely Dx and what is your management?

1. ITP
2. NAITP
3. Purpura Fulminans
4. ALL
5. Henoch-Scholein Purpura
6. DIC
7. TTP
8. MDS

Answer 26

5. HSP

HSP is most common in caucasian men aged 3-15yrs with 50% occuring by age 5yrs.

It is typically preceded by a viral infection 1-2 weeks prior and presents with purpura, abdominal pain and arthralgia (mainly seen as swelling of ankles and/or knees). More severe cases can present with nephrotic syndrome (oedema, hypoalbuminaemia and proteinuria) and renal failure, hence the urinalysis. Atypical presentations include headache, seizures and PHTN.

Ix is with FBC and blood film which shows thrombocytopenia with no abnormal cells and Urinalysis with U&E, dipstick and MC&S. Rare presentations may require a skin or renal biopsy showing neutrophil and monocyte infiltration with C3, fibrin and IgA deposition upon fluorescence.

Symptomatic relief is often required for the arthralgia with paracetamol.

Oral steroids are required if there is abdominal pain, severe oedema or scrotal involvement.

IV steroids are required if nausea/vomiting accompanies the abdominal pain or if there is nephrotic syndrome/ renal failure

The majority of cases (~90%) with resolve spontaneously within 4 weeks with ~33% have a further episode although this is less severe.

Question 27

A 3 y/o presents with a rash around the mouth and nose. It is erythematous with thick and dark yellow crusts and a few fluid filled lesions <5mm in diameter are present. It does not appear to be painful or pruritic and is quiet localised and superficial. There are no lesions on the inside of the mouth or the tongue. What is the most likely Dx and what is your management?

1. Non-bullous Impetigo
2. Bullous Impetigo
3. Cellulitis
4. Erysipelas
5. Necrotising fasciitis
6. Stevens-Johnson syndrome
7. Scarlet Fever

Answer 27

2. Non-bullous Impetigo

This is non-bullous impetigo typically caused by group-A beta-haemolytic strep.pyogenes as the crusts are thick and dark and the lesions are <5mm in diameter. The mucous membranes are also typically sparred. Bullous Impetgio is typically caused by Staph Aureus and presents with lighter, thinner crusts and bullae >5mm in diameter which start of clear -> turbid before rapidly bursting to form crusted lesions. Mucous membranes are often affected in Bullous Impetigo.

Both lesions present with an erythematous base and crusting, typically around the nose and mouth. The rash is rarely painful or pruritic. More severe cases can present with fever and lyphadenopathy.

If this was a neonate, you would observe for signs of sepsis as non-bullous impetgio may lead to sepsis in patients of this age.

Dx is a clinical one but you would want to swab for MRSA to exclude

Tx depends on the age and the severity of infection.

Neonates are treated with a Macrolide if MRSA is excluded (Oral if non-bullous and IV if Bullous). IV Vancomycin is 1st line if MRSA

Children with superficial and localised Impetigo are treated with topical Mupirocin.

Diffuse Impetigo that is still superficial is treated with oral Penicillin (Flucloxacillin) or 1st gen Cephalosporin (Cefalexin) if MRSA -VE. Oral Clindamycin or Trimethoprim/Sulfamethoxazole is 1st line if MRSA +Ve

Deep infection or signs of haematogenous spread is treated with IV Clindamycin or Penicillin (Nafcillin) if MRSA -Ve and Vancomycin if MRSA +ve

Intranasal Mupirocin can be given if the atient suffers from recurrent Impetigo

Prognosis is good with Tx with low risk of sepsis, cellulitis/erysipelas or glomerulonephritis

Follow-up is only required if the patient is immunosuppressed or a neonate due to the risk of sepsis

Question 28

A 3 y/o presents with a rash around the mouth and nose. It is erythematous with thin and light yellow crusts and a turbid, fluid filled lesions >5mm in diameter are present. It does not appear to be painful or pruritic and is quiet localised and superficial. There are lesions on the inside of the mouth. What is the most likely Dx and what is your management?

1. Non-bullous Impetigo
2. Bullous Impetigo
3. Cellulitis
4. Erysipelas
5. Necrotising fasciitis
6. Stevens-Johnson syndrome
7. Scarlet Fever

Answer 28

1. Bullous Impetigo

This is Bullous Impetgio, typically caused by Staph Aureus , as the crusts are light and thin with bullae >5mm in diameter which start of clear -> turbid before rapidly bursting to form crusted lesions. Mucous membranes are often affected in Bullous Impetigo. Non-bullous impetigo typically caused by group-A beta-haemolytic strep.pyogenes as the crusts are thick and dark and the lesions are <5mm in diameter. The mucous membranes are also typically sparred.

Both lesions present with an erythematous base and crusting, typically around the nose and mouth. The rash is rarely painful or pruritic. More severe cases can present with fever and lyphadenopathy.

Dx is a clinical one but you would want to swab for MRSA to exclude

Tx depends on the age and the severity of infection.

Neonates are treated with a Macrolide if MRSA is excluded (Oral if non-bullous and IV if Bullous). IV Vancomycin is 1st line if MRSA

Children with superficial and localised Impetigo are treated with topical Mupirocin.

Diffuse Impetigo that is still superficial is treated with oral Penicillin (Flucloxacillin) or 1st gen Cephalosporin (Cefalexin) if MRSA -VE. Oral Clindamycin or Trimethoprim/Sulfamethoxazole is 1st line if MRSA +Ve

Deep infection or signs of haematogenous spread is treated with IV Clindamycin or Penicillin (Nafcillin) if MRSA -Ve and Vancomycin if MRSA +ve

Intranasal Mupirocin can be given if the atient suffers from recurrent Impetigo

Prognosis is good with Tx with low risk of sepsis, cellulitis/erysipelas or glomerulonephritis

Follow-up is only required if the patient is immunosuppressed or a neonate due to the risk of sepsis

Question 29

A 4 y/o presents with fever and a diffuse maculopapular rash that is pruritic and came on the morning after the fever started. They also complain of headaches, nausea/vomiting, anorexia and arthralgia. They came into the hospital three weeks ago with a rash around the mouth for which they were given topical antibiotics. O/E you see a strawberry tongue and palpate raised cervical lymph nodes. What is the most likely Dx and what is your management?

1. Non-bullous Impetigo
2. Bullous Impetigo
3. Cellulitis
4. Erysipelas
5. Necrotising fasciitis
6. Stevens-Johnson syndrome
7. Scarlet Fever

Answer 29

7. Scarlet Fever

This patient’s Hx is suggestive of previous Impetigo which is a risk factor for Scarlet fever.

The first sign is a fever associated with lymphadenopathy, strawberry tongue, sore throat and flu-like symptoms. The maculopapular rash which begins on the head/neck before spreading to the trunk and extremities come ~12-48hrs later. Goose pimples with then develope and Pastia lines may be seen in the flexural creases due to bursting of capillaries.

Scarlet fever is caused by the Exotoxin of Group-A Streptococcus. It is most common in those aged 4-8yrs as those younger than this may still have maternal antibodies and those older are likely to have formed their own against the Exotoxin.

The Dx is predominently clinical with throat swab/rapid strep antigen testing confirming Dx

Tx is with 10 days or Penicillin (Macrolide if allergic) + supportive care (Paracetamol for fever, anti-histamines if pruritic and good hydration)

Prognosis is good with Tx as the fever resides within 12hrs and the rash dissapears with a degree of desquamation within a week. The risk of complications such as Glomerulonephritis, Pneumonia, Osteomyelitis and Rheumatic Fever is low with good Tx.

Question 30

A child presents with acute onset rash on both legs. There is no fever or flu-like symptoms. O/E you notice a cold-sore around the mouth but the mucosal membranes are free from any lesions. The rash itself is erythematous with a clearance zone and a central blister. What is the most likely Dx and what is your management?

1. Erythema Multiforme
2. Stephen-Johnson syndrome
3. Urticaria
4. Erythema contagiousum
5. Erythema Nodosum

Answer 30

1. Erythema Multiforme

Erythema Multiforme can be caused by a wide array of factors.
Drugs = Penicillins, Phenytoin and Sulphonamides
Inflammatory processes = RA, SLE, UC and Sarcoidosis
Infection = HSV, TB, Mycoplasma, Hep A and EBV
Radiotherapy
Malignancy = Haematological

The presence of a cold-sore suggests HSV.

The rash comes on acutely and has a characteristic target appearance. lesions on the extremities have a clearance zone whereas targetoid lesions on the trunk do not. EM major will also have mucosal involvement. Otitis media and lung involvement suggests Mycoplasma although lung involvement may also be due to TB or Sarcoidosis. Hepatomegaly suggests Hep A.

EM is less common in children than adults and rare <3 yrs but children tend to have more severe forms of infection.

Dx is clinical with tests to supportive underlying cause

• FBC and CRP for infectious signs
• U&E to check hydration
• LFT if Hepatomegaly
• Serology (HSV, Hep A, anti-CCP, anti-dsDNA,Ro/La/Sm)
• CXR

Tx

• Supportive with Emollients and topical steroids to reduced inflammation and prevent cracking
• Analgesia if pain
• Oral aciclovir/Valaciclovir if HSV
• Oral Macrolide or Doxycycline if Mycoplasma
• RIPE if TB

Prohnosis is good with the conditions typically self-limiting and recovering within 2-3 weeks with no scarring. Risk of secondary bacterial infection is low. Recurrent EM should be Tx with prophylactic antiviral therapy