Saturday, 1 October 2016

Pityriasis alba sparing the face

Pityriasis (Gk pityron, bran) alba (L albus, white) is a pattern of dermatitis in which hypopigmentation (with branny scaling) is the most conspicuous feature.  Erythema (with branny scaling) usually precedes the development of hypopigmentation but this is often relatively mild. At times, there may be initial minimal serous crusting.  The hypopigmentation is more noticeable in pigmented skin, summer and after sun tanning. The scaling is more noticeable in winter. 

The individual lesion is a rounded, oval or irregular hypopigmented patch that is usually not well marginated.  The course is extremely variable.  Post inflammatory hypopigmentation (without scaling) ensues before resolution occurs. Recurrent crops of new lesions may develop at intervals.  Pityriasis alba is sometimes a manifestation of atopic dermatitis but it is certainly not confined to atopic individuals.

Although pigment is reduced, melanocyte numbers are not (the activity is decreased) and may even be increased relative to healthy skin.

Pityriasis alba occurs predominantly in children between the ages of 3 and 16 years. Both sexes are equally susceptible. The lesions are often confined to the face, and are most common around the mouth, chin and cheeks.  In 20% of affected children the neck, arms and shoulders are involved as well as the face.  Less commonly, the face is spared and there are scattered lesions on the trunk and limbs as shown on this patient’s skin.

The age incidence, the fine scaling and the distribution of the lesions usually suggest the diagnosis. Mycosis fungoides may present with lesions clinically resembling pityriasis alba. This condition may also be difficult to distinguish histopathologically, so follow-up and repeat biopsies are sometimes required.

Topical calcineurin inhibitors, pimecrolimus and tacrolimus, have been reported to speed recovery of skin colour.

Topical pimecrolimus has been reported to speed recovery of skin colour as shown here.
This page was last updated in October 2016. 

Main Works of Reference List (The first eight are my top favourites)

  • British National Formulary
  • British National Formulary for Children
  • Guidelines (BAD - BASHH - BHIVA - Uroweb)
  • Oxford Handbook of Genitourinary Medicine, HIV, and Sexual Health
  • Oxford Handbook of Medical Dermatology
  • Rook's Textbook of Dermatology
  • Simple Skin Surgery
  • Weedon's Skin Pathology
  • A Concise Atlas of Dermatopathology (P Mckee)
  • Andrews' Diseases of the Skin
  • Andrology (Nieschlag E FRCP, Behre M and Nieschlag S)
  • Bailey and Love's Short Practice of Surgery
  • Davidson's Essentials of Medicine
  • Davidson's Principles and Practice of Medicine
  • Fitzpatrick's Colour Atlas and Synopsis of Clinical Dermatology (Klaus Wolff FRCP and Richard Allen Johnson)
  • Fitzpatrick’s Dermatology in General Medicine
  • Ganong's Review of Medical Physiology
  • Gray's Anatomy
  • Hamilton Bailey's Demonstrations of Physical Signs in Clinical Surgery
  • Hutchison's Clinical Methods
  • Lever's Histopathology of the Skin
  • Lever's Histopathology of the Skin (Atlas and Synopsis)
  • Macleod's Clinical Examination
  • Martindale: The Complete Drug Reference
  • Oxford Handbook of Clinical Examination and Practical Skills
  • Oxford Textbook of Medicine
  • Practical Dermatopathology (R Rapini)
  • Sexually Transmitted Diseases (Holmes K et al)
  • Statistics in Clinical Practice (D Coggon FRCP)
  • Stockley's Drug Interactions
  • Treatment of Skin Disease: Comprehensive Therapeutic Strategies
  • Yen & Jaffe's Reproductive Endocrinology