Friday, 11 April 2014

Black heel

Black heel (talon noire) lesions or calcaneal petechiae result from lakes of haemorrhage in the stratum corneum. The red blood corpuscles are extravasated into the lower epidermis from dilated vessels in the papillary dermis. They undergo transepidermal elimination in the form of old blood during the progressive maturation of the epidermis and overlying stratum corneum. The condition results from shear–stress rupture of the papillary capillaries in a traumatic process particularly where sudden twisting of the heel occurs. The condition starts as closely aggregated groups of bluish black specks that occur suddenly at the back or side of the heel just above the hyperkeratotic edge of the foot.

Lesions comparable in appearance, pathogenesis, and pathology occur in other situations such as jogger’s toenail, and weeder’s thumb. The term posttraumatic punctate haemorrhage has been proposed as a unifying term.

It may be mistaken for a plantar wart, a tattoo, or even a melanoma (seeming confluence may lead to mimicry of melanoma). But when there is a history of sudden appearance of the pigmented lesions at a typical site, diagnosis is rarely in doubt. Viral warts can also produce a black stippled appearance because of extravasation of red blood corpuscles, but the skin surface is generally abnormal. Occasionally, melanoma or atypical melanocytic hyperplasia will need to be excluded. With black heel, the patient and the skin physician can usually be reassured by carefully paring the affected area, thereby completely removing the abnormality. Dermatoscopy shows “globules on ridges”.

Treatment is unnecessary.

This page was last updated in April 2014

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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