This document discusses skin rashes and provides guidance on evaluating and diagnosing them. It notes that rashes can be caused by many factors and outlines important questions to ask patients about symptoms. Red flags that may indicate a serious condition include rashes covering over 90% of the body, punched-out lesions in eczema patients, fever, or an unwell patient. The examination should document characteristics of the rash like appearance, texture, distribution and progression over time. Common rash causes mentioned include medications, eczema, psoriasis, urticaria, impetigo, and viral or bacterial infections.

1. SKIN RASHES- RED
FLAG SYMPTOMS

2.  Skin rashes are a very common reason for
people to present to general practice. Often, they
will present early and in an undifferentiated way
making them difficult to diagnose.
 They can be a sign of many different
pathologies and a good history is important.
Patients can find rashes very irritating and will
sometimes be worried about them being
infectious. They may also worry about the
cosmetic appearance. Some may have already
been to a chemist and tried various over-the-
counter products.

3.  Rash covering more than 90% of a person’s body surface area
 Punched-out lesions in a person with eczema
 Fever
 An unwell patient (adult or child)
 Diarrhoea
 Nausea and vomiting
 Headache
 Photophobia
 Non-blanching rash
 Arthralgia and muscle pains
 Pharyngitis
 Blisters and bullae
 Scalded skin appearance
 Suspicious skin lesions

4.  A history of a skin rash should include the duration it
has been present, and whether it is itchy, sore, tingly or
scabbing. Associated symptoms like fever, cough, sore
throat, joint pain and general health are important.
 In children with rashes, ask about nausea and vomiting,
headaches, photophobia and whether the rash is
blanching.
Viral meningitis rash in a 6-week-old
baby:

5.  When examining a rash, it is important to
expose the patient to be able to look at the extent
of the rash, whilst maintaining the patient’s
dignity as much as possible. Consideration
should be given to the colour, size, appearance
and texture, shape, distribution and progression
over time of the rash.
 The predominant site of the rash should be
noted. It is important to document if it is
blanching or non-blanching and to look for any
field change.

6. Erythema:
redness

7. Macule: small,
flat, localised
area of colour
change

8. Nodule:
elevated skin
lesion of
>0.5cm
diameter

9. Papule:
elevated skin
lesion of
<0.5cm
diameter

10. Petechiae:
pinpoint red
spots under the
skin

11. Plaque: raised,
flat lesion

12. Pruritis: itch

13. Purpura:
haemorrhagic
area in the skin

14. Pustule: pus-
filled lesion

15. Vesicle: small,
fluid-filled
blister

16.  In most circumstances, rashes will be diagnosed on the
basis of history and thorough examination. If there is
still doubt, investigations should be based on the likely
differential diagnosis.
 Causes of rash
 Medications including sertraline, allopurinol,
carbamazepine, lamotrigine and the `oxicam’ class of
anti-inflammatory drugs can cause Stevens-Johnson
syndrome, which may start with flu-like symptoms,
cough, joint pains and headache and progress to non-
pruritic rash with large blisters.
 Non-blanching rash will not always develop in
meningitis and other symptoms include a high
temperature, vomiting, headache, stiff neck,
photophobia and unresponsiveness.

17.  Psoriasis presents with red, raised inflamed patches that
may have whitish-silver scales or plaques. These may be
itchy or painful.
 As well as the face, acne can involve the neck, back and
chest, and feature papules, pustules, comedones and
pseudocysts. Topical antibiotics are usually used in
combination, most commonly with benzoyl peroxide.
 Impetigo starts with red sores or blisters on exposed
areas such as the face and hands. These burst and leave
crusty, golden brown patches.

18.  POSSIBLE CAUSES
 Medications including NSAIDs and antibiotics
 Atopic eczema
 Psoriasis
 Urticaria
 Impetigo
 Acne vulgaris
 Rosacea
 Seborrhoeic dermatitis

19.  Tinea
 Viral infection
 Stevens-Johnson syndrome
 Toxic epidermal necrolysis
 Meningococcaemia
 Staphylococcal scalded skin syndrome
 Necrotising fasciitis

20. THANK YOU