March 2022

Atypical Wounds: What Every Clinician Should Know

By Windy Cole, DPM, CWSP

The prevalence of atypical wounds has not been studied extensively, but it has been estimated that 20% of all chronic wounds are due to unusual causes.1,2 The ability to identify and treat chronic wounds caused by uncommon etiologies is an important skill. Unfortunately, it can take years of clinical experience to master.

One of the first indications that a chronic wound may be atypical is that it lacks a history of an acute trauma and it does not fit into a known clinical category (diabetic foot ulcer [DFU], venous leg ulcer [VLU], or pressure injury). If a wound does not seem to fit into any of these categories AND fails to respond to standardized wound therapies, clinicians should dig deeper to ascertain the correct diagnosis and begin to provide the appropriate wound care.

There are several wound characteristics that can alert the clinician that a wound may have an atypical etiology.3

  • Unusual location: A wound that appears to be venous in nature, but does not appear on the typical location for a VLU.
  • Asymmetry: Wounds with irregular edges should be closely monitored.
  • Excessive or friable granulation tissue: When granulation tissue has disproportionate cell growth or bleeds very easily, this may be an indication of an underlying pathologic process.
  • Patient age: It would be very unusual for a young patient to present with peripheral arterial disease and gangrene of a toe.
  • Radiation to the area: Radiation can lead to cell death and tissue necrosis.
  • Remote history of trauma: Repetitive trauma can lead to pathological changes in the skin and surrounding tissues.
  • Pain: When patients present with pain out of proportion to clinical appearance, an atypical wound should be ruled out.
  • Pigmented lesions: This can indicate an inflammatory or malignant process is occurring.
  • Vegatative growth: Fungating tissue growth can indicate an infective process or be a sign of malignancy.


Identifying an atypical wound can be a difficult undertaking. A detailed history and physical exam are the 2 most critical factors in assuring an accurate diagnosis is made. Obtaining in-depth medical, travel, recreational, and occupational histories should be gathered from the patient. A complete physical exam and wound assessment including wound measurement, location, staging, tissue character and color, odor, exudate quality and amount, peri-wound tissue appearance, and pain are important details to notate. If a chronic wound persists despite appropriate wound care treatments and typical wound etiologies are ruled out based on these findings, additional diagnostic testing such as a skin biopsy is appropriate.


Atypical wounds are rare and their pathophysiology is not well understood. The diagnosis and management of these ulcer types is a real challenge to physicians. Skin biopsy plays a pivotal role in making the diagnosis and should be performed in all cases of refractory wounds. Additional microbiological, immunohistochemical, and laboratory testing may be warranted to confirm the proper diagnosis. Wound progression is often unpredictable and wound care therapies are not standardized. Early suspicion and expert examination is of the utmost importance in the treatment of atypical wounds. A ‘wait and see’ attitude may be detrimental when dealing with complex atypical wounds.

Windy Cole, DPM, CWSP, is an adjunct professor and Director of Wound Care Research at Kent State University College of Podiatric Medicine and serves on the LER Editorial Advisory Board.

  1. Shanmugam VK, Angra D, Rahimi H, McNish S. Vasculitic and autoimmune wounds. J Vasc Surg Venous Lymphat Disord. 2017;5(2):280-292.
  2. Shanmugam VK, Schilling A, Germinario A, et al. Prevalence of immune disease in patients with wounds presenting to a tertiary wound healing centre. Int Wound J. 2012;9(4):403-11.
  3. Hamm RL, Shah JB. Atypical Wounds. Text and Atlas of Wound Diagnosis and Treatment: 2nd edition. New York: McGraw Hill Education. 2019;235-268.

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