Facial Rash

Unlike most of the other ‘skin’ sections, this section is presented according to the rash’s distribution. This is because it is a common presentation, one with a wide differential and one which causes the patient significant concern, largely because of the cosmetic impact. Occasionally, it can be caused by, or represent, significant pathology. Individual facial spots – such as basal cell carcinoma – aren’t considered here.

Published: 2nd August 2022 | Updated: 15th August 2022

Differential diagnosis

Common Diagnoses

  • Acne
  • Rosacea
  • Seborrhoeic Eczema
  • Impetigo
  • Perioral Dermatitis

Occasional Diagnoses

  • Chloasma
  • Sycosis Barbae
  • Drug Side Effect: Especially Phototoxicity
  • Infection (e.g. Herpes Zoster and Simplex, Cellulitis, Chickenpox, Slapped Cheek)
  • Allergic Eczema
  • Acne Excoriée
  • Post Inflammatory Hypo- or Hyperpigmentation
  • Pityriasis Alba
  • Petechiae from Coughing/Vomiting/Straining
  • Other Generalised Skin Diseases (e.g. Psoriasis, Vitiligo)

Rare Diagnoses

  • Stevens–Johnson Syndrome
  • SLE
  • Mitral Flush
  • Tuberous Sclerosis
  • Lupus Vulgaris
  • Sarcoidosis
  • Dermatomyositis

Ready reckoner

Key distinguishing features of the most common diagnoses

AcneRosaceaSeborrhoeic Eczema ImpetigoPerioral Dermatitis
Mainly Around Mouth PossibleNoNo PossibleYes
Rash Elsewhere PossibleNo Possible PossibleNo
Age >40NoYes Possible Possible Possible
Papules and PustulesYesYesNo PossibleYes
Rapid Response to AntibioticsNoYesNoYesYes

Possible investigations

Likely: None.

Possible: FBC, ESR/CRP, autoantibody screen, CPK.

Small Print: Viral or bacterial swabs, skin biopsy, muscle biopsy.

  • FBC: WCC raised in any infection; may be normochromic, normocytic anaemia in SLE.
  • ESR/CRP, autoantibody screen: ESR/CRP likely to be raised in infection and SLE; autoantibodies may be positive in the latter.
  • CPK: Elevated in dermatomyositis.
  • Viral or bacterial swabs: To help diagnosis in obscure cases or if secondary infection suspected.
  • Skin biopsy; muscle biopsy: The former for suspected lupus vulgaris or sarcoidosis; the latter to confirm dermatomyositis.

Top Tips

  • Do not underestimate the possible impact of a facial rash on a patient’s life. The cosmetic effect may be devastating.
  • A therapeutic trial of antibiotics in acne may take up to 3 months to take effect – ensure the patient is aware of this.
  • Remember that impetigo may simply represent superinfection of an underlying skin problem, such as eczema, which will require treatment in its own right.
  • Check on OTC medication usage. In particular, remember that hydrocortisone 1% cream is available over the counter – inappropriate use might aggravate rosacea and perioral dermatitis.
  • Parents are sensitised to non blanching rashes. They can be reassured that such a rash restricted to the face (indeed, restricted to the entire distribution of the superior vena cava) is not due to meningitis.

Red Flags

  • A complaint of dramatic facial ‘sunburn’ in the elderly may well represent a phototoxic reaction – check the drug history.
  • Beware the acute onset of unilateral unexplained facial erythema with mild oedema, especially in an elderly patient. This may well be the start of cellulitis or herpes zoster.
  • Warn patients with facial zoster or herpes simplex infection near the eye to report any ocular problems.
  • Acne excoriée may be a marker of significant psychiatric pathology.
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Website disclaimer

Pulse Reference is based on the best-selling book Symptom Sorter.

The experts behind Pulse Reference are Dr Keith Hopcroft who is the co-author of Symptom Sorter, a GP in Essex and Pulse’s editorial advisor and Dr Poppy Freeman, a GP in Camden and also a clinical advisor to Pulse.

This website is for clinical guidance only and cannot give definitive diagnostic information. Practitioners should work within the limits of their individual professional practice, seek guidance when necessary and refer appropriately.