A patient complains of a painful, cone-shaped, hard lesion on the fifth toe. The nurse identifies this as a corn. What is the primary cause for the development of this condition?

Appeared in: NORCET 1 - 2020

Explanation

A corn (heloma) is a protective thickening of the epidermis (hyperkeratosis) in response to repeated mechanical stress.
The primary cause is chronic, localized pressure or friction, most commonly from ill-fitting footwear that compresses a toe against the shoe or an adjacent toe.
The cone-shaped structure of a hard corn presses into the deeper layers of the skin, causing pain, as described in the question.

Option A: A fungal infection (tinea pedis) typically causes itching, scaling, and maceration between the toes, not a discrete, hard, cone-shaped lesion.
Option C: A viral infection with HPV causes warts (verrucae), which are distinguished from corns by their tendency to bleed when pared and the presence of small black dots (thrombosed capillaries).
Option D: Peripheral vascular disease (PVD) impairs circulation, which increases the risk of ulceration and poor healing of foot lesions, but it does not directly cause the formation of a corn.

Clinical Relevance

Nursing practice connection: Use the key finding related to Etiology of corns (helomas) and foot assessment to guide bedside assessment, documentation, and the next nursing action.
Nurses play a crucial role in patient education regarding proper footwear selection and foot hygiene to prevent corns and other foot problems.
Assessment for corns is a key part of foot care, especially in high-risk populations like patients with diabetes or PVD, where a simple corn can lead to severe complications like ulcers and infection.
What if? If the patient also had diabetes, the presence of a corn would be significantly more concerning due to the increased risk of neuropathy (loss of sensation) and poor circulation, which can lead to non-healing ulcers and potential amputation. The nursing priority would shift to aggressive prevention and professional podiatric care.

How to Approach the Question

First, analyze the clinical presentation described in the stem: a 'painful, cone-shaped, hard lesion on the fifth toe.'
Recognize that this description is the classic definition of a hard corn (heloma durum).
Next, recall the primary etiology of corns. The key mechanism is hyperkeratosis resulting from chronic, localized pressure.
Evaluate each option against this known cause. Options A (fungal), C (viral), and D (vascular) represent different pathophysiological processes.
Select the option that describes the direct mechanical cause of corn formation, which is pressure and friction, most often from footwear.

Concept Tested & Keywords

Concept Tested: Etiology of corns (helomas) and foot assessment
Stem keywords: painful lesion, cone-shaped, hard lesion, fifth toe, corn, primary cause
Lead-in keywords: What is
Clinical cues: Location: fifth toe - a common site for pressure from shoes.
Clinical cues: Description: painful, cone-shaped, hard - classic signs of a hard corn (heloma durum).

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E6 Nursing Brunner Adult Health 3SA Vol 1 Part 4 p. 146-148

Practise the full NORCET 1 - 2020

Attempt every question from this paper in a timed mock, then review the full solution for each one.