Why fever with a rash and mouth sores matters
A painful rash with sores in the mouth and red eyes can be a viral illness, an infection, or a severe reaction that behaves like a burn. Find out which quickly: assess how much skin and how many surfaces are involved, and protect the eyes, fluids and nutrition.
What to ask in the history
- When the rash started and how fast it has spread; is the skin painful
- Every medicine in recent weeks, including antibiotics, painkillers and anything bought without a prescription
- Fever, sore throat, cough
- Eyes, genitals, passing urine
- Blisters or peeling
- Previous reactions to medicines
- Cold sores, HIV
Red flags
- Blistering or peeling skin
- Sores on more than one surface (mouth, eyes, genitals)
- Eye pain or redness
- Low blood pressure
- Breathing difficulty
- Unable to eat or drink
What to examine
- Observations
- Skin: the type of lesion, how much of the body is involved, pain
- Whether the skin slides off with gentle pressure
- Mouth, eyes, genitals
- Lymph nodes, chest
First investigations
- Full blood count, kidney and liver function, electrolytes, glucose
- Blood cultures
- Skin biopsy
- HIV test, mycoplasma test
- An urgent eye review
- A recognised severity score
Differential diagnosis of fever with a rash and mouth sores
Grouped, not ranked. Which one fits this patient is for you to work out in the case.
Infections
- Herpes simplex
- Mycoplasma
- Staphylococcal scalded skin
- Viral rashes such as measles or chickenpox
Reactions to medicines
- Stevens-Johnson syndrome or toxic epidermal necrolysis
- DRESS
- Erythema multiforme major
Other
- Pemphigus
- Pemphigoid
Common mistakes
- Continuing a medicine that could be the cause.
- Underestimating the fluid lost through damaged skin.
- Missing eye involvement.