Problem refinement

Further exploration around the nature of the rash and if any other symptoms have been noticed should be conducted. Inspection of the skin shows the rash blanches on pressing and feels rough to the touch. Blanching is seen with (e.g.) roseola, allergy and scarlet fever. 

You already have determined that the distribution of the rash seems wrong for roseola and in allergy you would not expect prodromal symptoms or fever – yet the nature of the rash does fit with scarlet fever. 

Scarlet fever affects the tongue and so, on inspection, you would expect this to be inflamed if scarlet fever is indeed the cause. The tongue is red and inflamed. Both blanching rash and red tongue fit with a diagnosis of scarlet fever.

Although you are reasonably confident that scarlet fever is the diagnosis, it is important to consider other possible causes too. Jake does not take any medicines, eliminating a drug-induced problem and reducing the chances of erythema multiforme (50 per cent of cases have a drug-induced history). Additionally, to eliminate conditions associated with travel, his parents should be asked about any recent holidays. Answers to such questions are all negative.

While German measles/measles are vaccine preventable, these cannot be totally ruled out due to incomplete vaccination rates leading to small numbers of UK confirmed cases each year. Jake’s parents confirm he is up to date with all vaccines. 

Red flags

The location of the rash is not consistent with lupus and in arthritis joint pain and swelling would be a prominent feature. Kawasaki disease, while similar to scarlet fever, shows other symptoms such as conjunctivitis, cracked lips and swollen hands/feet.

Management: self-care options

To help treat the fever OTC paracetamol or ibuprofen could be recommended. Jake should also be encouraged to drink fluids and his parents should consider giving him soft food to eat to help with the sore throat.

To minimise spread, hygiene measures should be put in place such as thorough and frequent hand washing and avoiding sharing towels with family members.  

Signposting and safety netting

Scarlet fever is a notifiable disease and the local health protection team must be told. You tell Jake’s parents they need to see their GP as you believe their son has scarlet fever and this needs to be confirmed by the doctor. 

You tell them if he has scarlet fever, then the GP will prescribe antibiotics (usually penicillin 250mg qds x 10 days) and his symptoms should resolve in approximately one week. The GP is likely to want to make a follow-up appointment to make sure everything is all right with Jake.