Skip to content

Common Rashes Module

SHARE VIA:

TopicCommon rashes
AuthorAoife Fox
DurationUp to 2 hours
Equipment requiredNone
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Game
    Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline.

Definitions/rash description:

  • Macule: a flat area of colour change <1 cm in size (e.g., viral exanthem [such as measles and rubella], morbilliform drug eruption).
  • Patch: a large macule >1 cm in size (e.g., viral exanthem [such as measles and rubella], morbilliform drug eruption).
  • Papule: a raised area <1 cm in size (e.g., wart).
  • Nodule: a larger papule, >1 cm in size (e.g. nodular prurigo). 
  • Plaque: a flat-topped raised area (a cross between a nodule and a patch; e.g., psoriasis).
  • Vesicle: a small fluid-filled lesion (blister) <0.5 cm in size (e.g. varicella, eczema herpeticum).
  • Bulla: a larger vesicle >0.5 cm (e.g. bullous impetigo).
  • Pustule: a pus-filled lesion (e.g. folliculitis).
  • Wheal: a transient raised papule or plaque caused by dermal oedema (e.g. urticaria)
  • Scale: flakes of stratum corneum (e.g. eczema, psoriasis).
  • Crust: dried serum, blood, or purulent exudate on the skin surface (e.g. impetigo).
  • Erosion: loss of epidermis, heals without scarring (e.g. Stevens-Johnson syndrome, toxic epidermal necrolysis).
  • Ulcer: loss of epidermis and dermis, heals with scarring (e.g. venous ulcer, pyoderma gangrenosum).
  • Excoriation: loss of epidermis following trauma such as scratching (e.g. pruritus).
  • Fissure: a split in the skin (e.g. angular cheilitis, palmoplantar keratoderma).
  • Lichenification: thickening of the skin with accentuation of skin markings (e.g. chronic eczema, lichen simplex chronicus).
  • Purpura: an area of colour change (red or purple) due to bleeding into the skin; does not blanch on pressure (e.g. vasculitis, disseminated intravascular coagulation).
  • Petechia: a pin-point purpuric lesion (e.g.,vasculitis, disseminated intravascular coagulation).
  • Ecchymosis: a larger area of purpura (e.g. vasculitis, disseminated intravascular coagulation).
Some important points to note in history:
  • Where did the rash start?
  • Sequence of the rash?
  • Type of rash?
  • Time of onset and duration?
  • Involvement of palms and soles?
  • Involvement of mucous membranes?
  • Involvement of conjunctiva?
  • Desquamating?
  • Systemic involvement?
  • Associated symptoms – fever/cough/conjunctivitis/runny nose/sore throat/strawberry tongue/itchiness/pain/weakness/headache/lymphadenopathy/swollen extremities/nausea/vomiting/diarrhoea? 
  • Exposures – immunizations/pets/foreign travel/bites (insects/ticks)/recent injury to skin/sexual history/sick contacts?

Common childhood rashes

The terminology for all but fifth disease is not used anymore, however, should anyone be curious here they are:

Also known as..What causes it?When?What rash?Where is the rash?FeverAssociated findings
First diseaseMeaslesParamyxovirusWinter – spring Erythematous, confluent, maculopapularBegins at the hairline spreads inferiorlyHigh feverKoplik spots, cough, coryza and conjunctivitis, Forchheimer spots
Second diseaseScarlet feverStreptococcus pyogenesAutumn – spring Generalised erythema with a sandpaper textureBegins on the face and upper part of trunk and spreads inferiorlyHigh feverPastia lines, Forchheimer spots, strawberry tongue, exudative pharyngitis, abdominal pain, rheumatic fever, circumoral pallor
Third diseaseRubellaRubivirusLate winter – spring Rose-pink, maculopapularSpreads inferiorlySlightly high feverLymphadenopathy, arthralgias, Forchheimer spots
Fourth diseaseThe existence of “fourth disease” is controversial. It was described as a generalised maculopapular rash and desquamation. This exanthema may be staphylococcal scalded skin syndrome
Fifth diseaseSlapped cheekParvovirus B19Winter and spring“Slapped cheek” appearance, lacy reticular rashErythematous cheeks, reticular extremities Slightly high feverRash, waxes and wanes over weeks, arthritis, aplastic crisis
Sixth diseaseRoseola Human herpesvirus 6 and 7SpringRose-pink, maculopapularNeck and trunk High feverLymphadenopathy, febrile seizures, Nagayama spots
Others of note..ChickenpoxHerpes zoster virusLater winter and early springVesicles on erythematous base, crustsBegins on face and trunk and spreads centripetallyHigh feverPruritus
Hand-foot-and-mouthCoxsackie A virusLate summer or early winterElliptical vesicles on an erythematous base, oral vesicle, erosionsMouth, hands and feetHigh feverVesicles on the hands, feet and in the mouth

Forchheimer spots: rose coloured spots on the soft palate that may coalesce into a red blush and extend over the fauces

Koplik spots: clustered white lesions on the buccal mucosa. They are pathognomonic for measles.

Pastia lines: where pink or red lines formed of confluent petechiae are found in the skin creases.

Nagayama spots: erythematous papules on the mucosa of the soft palate and the base of the uvula. You may see these present on the fourth day in two thirds of patients with roseola.

(based on case from RCEM Learning RCEM Learning – Common Childhood Exanthems)

Mark is a 3-year-old boy brought to the ED by his mother with a rash, temperatures and decreased oral intake. His older brother has a similar rash and illness and mum reports that there was an outbreak of chickenpox in the older brother’s school. 

On exam you note a quiet child with a diffuse vesicular rash. On palpation he has generalised lymphadenopathy.

What are the differentials of chicken pox in this case?

What is the incubation period of chicken pox? How long will Mark be infective?

What investigations are necessary?

How would you manage this illness? What treatment would you give?

What patients would you give anti-VZV immunoglobulin to?

Mark’s mum tell you that she has a 2-week old baby at home – what will you do?

What complications of chickenpox can occur?

Mum tells you that the children’s childminder is pregnant what advice do you give?

Discussion point – Do you use NSAIDs?

What are the differentials?

What is the incubation period? How long will Mark be infective?

What investigations are necessary?

How would you manage this illness? What treatment would you give?

What patients would you give anti-VZV immunoglobulin to?

Mark’s mum tell you that she has a 2-week old baby at home – what will you do?

What complications of chickenpox can occur?

Mum tells you that the children’s childminder is pregnant what advice do you give?

Do you use NSAIDS?

(Based on a case from the American Academy of dermatology – American Academy of Dermatology – Viral exanthems)

Caleb is a 9-year-old boy who presents for evaluation of fever and rash. His mother noted a fever of 40 °C two days ago. He appeared well and was eating and playing normally, so his mother was not alarmed. After the fever resolved, Caleb developed red rash that progressed rapidly over the past 24 hours.

What is the most likely diagnosis?

What are the differentials?

What is the cause of roseola?

Who gets it?

How is it spread?

What are the signs and symptoms of roseola?

How is it diagnosed?

What is the treatment?

What are the complications from roseola?

What is the most likely diagnosis?

What are the differentials?

What is the cause of roseola?

Who gets it?

How is it spread?

What are the signs and symptoms of roseola?

How is it diagnosed?

What is the treatment?

What are the complications from roseola?

What advice would you give Caleb’s mother with regards to febrile convulsions?

A 5-year-old girl, Emma, attends the ED with after being unwell for the last 3 days. It initially started out with fever, headache and a sore throat. She then developed a rash 24 hours ago. Her parents report that the rash started on her abdomen and spread to the neck and arms and legs and it feels rough to touch. 

On exam she has a sandpaper type rash on her trunk and limbs which is more pronounced in flexures. 

What is the most likely diagnosis?

What other symptoms might Emma have?

What is it caused by?

What are the differential diagnoses?

How is the diagnosis confirmed? What investigations will you do?

What is the treatment? Why do you treat?

Discussion point – Evidence for antibiotic therapy 

What are the possible complications? How can you categorise them?

What advice do you give to Emma’s parents in order to prevent transmission of Scarlet fever?

Is there anything else you need to do?

What is the most likely diagnosis?

What other symptoms might Emma have?

What is it caused by?

What are the differential diagnoses?

How is the diagnosis confirmed? What investigations will you do?

What is the treatment? Why do you treat?

What are the possible complications? How can you categorise them?

What advice do you give to Emma’s parents in order to prevent transmission of scarlet fever?

Is there anything else you need to do?

(Based on Life in the Fast Lane case – LITFL – Kawasaki Disease)

Alex, a 4 year-old boy has been brought to the emergency department by his worried parents. He has had fevers for the past 6 days. They are concerned because he is not getting better despite repeated visits to a number of doctors. Each time they were told he had a viral illness.

On examination you note the presence of bilateral conjunctivitis, and erythematous rash on his torso and limbs, a 4 cm tender left-sided cervical lymph node and a diffusely red pharynx.

What is the most likely diagnosis?

How is the diagnosis made?

Who gets this condition?

What are the important differential diagnosis?

What investigations should be performed?

What complications may occur?

What specific treatment is required?

Discussion point – Incomplete Kawasaki Disease: Another child, Sarah, attends the ED with 6 days of fever. On exam you find a strawberry tongue and cervical lymphadenopathy >1.5cm. No other signs of Kawasaki disease are present. What might you consider?

Discussion point – Is there a roll for steroids in Kawasaki disease?

What is the most likely diagnosis?

How is the diagnosis made?

Who gets this condition?

What are the important differential diagnosis?

What investigations should be performed?

What complications may occur?

What specific treatment is required?

Another child, Sarah, attends the ED with 6 days of fever. On exam you find a strawberry tongue and cervical lymphadenopathy >1.5cm. No other signs of Kawasaki disease are present. What might you consider?

Incomplete Kawasaki disease

DFTB – Kawasaki Disease

Very easily missed
Makes up 15-20% of all cases
Patients with incomplete KD, particularly those <6 months of age and older children, may experience significant delays in diagnosis and these children are at high risk of developing coronary artery abnormalities.

Consider KD if:

  • Infants <6 months old with prolonged fever and irritability
  • Infants with prolonged fever and unexplained aseptic meningitis
  • Infants or children with prolonged fever and unexplained or culture-negative shock
  • Infants or children with prolonged fever and cervical lymphadenitis unresponsive to antibiotic therapy
  • Infants or children with prolonged fever and retropharyngeal oroparapharyngeal phlegmon unresponsive to antibiotic therapy

Some pitfalls…

How could you differentiate between Kawasaki disease and scarlet fever?

How could you distinguish between incomplete Kawasaki disease and measles?

Is there a role for steroids in Kawasaki disease?

Question 1

Answer 1

Question 2

Answer 2

Question 3

Answer 3

Question 4

Answer 4

Question 5

Answer 5



Please download our Facilitator and Learner guides

Author

  • Aoife Fox is an emergency medicine trainee with an interest in medical informatics. She spends her time nurturing her sourdough starter and talking about her sourdough starter.

KEEP READING

No data was found

Leave a Reply

Your email address will not be published. Required fields are marked *

DFTB WORLD

EXPLORE BY TOPIC