Flat and painless thickened portion of epidermis consisting of mass of horny, keratotic cells formed by local pressure or friction found on palm or undersurface of foot is called

1. A

   Plantar warts

2. B

   Corns

3. C

   Athlete's foot

4. D

   Callus

Appeared in: ESIC Nursing Officer-7July 2024

Explanation

• A callus is defined as a thickened area of the epidermis caused by persistent pressure or friction, which perfectly matches the description in the question stem.
• Key characteristics of a callus are that it is typically diffuse, flat, and painless, unlike other common foot lesions.
• Calluses commonly form on weight-bearing areas like the soles of the feet or on the palms of hands from manual labor, consistent with the locations mentioned in the question.

Why Other Options Were Wrong

• Option A: Plantar warts are caused by a viral infection (HPV), not by pressure or friction. They are typically painful when squeezed side-to-side and often have small black dots (thrombosed capillaries).
• Option B: Corns, while also caused by pressure, are distinct from calluses. They are smaller, conical, have a hard central core, and are typically painful upon direct pressure.
• Option C: Athlete's foot (tinea pedis) is a fungal infection. It presents as an itchy, scaling rash with redness and fissures, not as a thickened, horny mass of cells.

Related Visual

• Visual 1: Comparative Chart - An infographic visually comparing the cross-section and surface appearance of a callus, corn, and plantar wart to highlight differences in structure (flat vs. conical core vs. vascular roots).
• Visual 2: Clinical Images - A set of four images showing the typical clinical presentation of a callus, a corn, a plantar wart, and athlete's foot on the human foot.

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Differentiation of common benign skin lesions of the foot as background academic context rather than a clinical decision trigger.
• Nurses play a crucial role in patient education regarding foot care, especially for preventing pressure-related skin issues. This includes advising on appropriate footwear and hygiene.
• A key patient safety concern is in the diabetic population. Due to peripheral neuropathy, a patient may not feel the pain from a developing callus or corn, which can break down and lead to a non-healing diabetic foot ulcer. Nurses must perform and teach regular foot inspections.
• What if? If the patient described in the question also had diabetes and poor vision, the priority nursing intervention would shift from simple education to arranging a referral to a podiatrist for safe removal and implementing a family/caregiver teaching plan for daily foot inspection.

How to Approach the Question

• First, break down the question stem into key descriptive words: 'flat', 'painless', 'thickened', 'pressure or friction'.
• Next, evaluate each option against this set of descriptors.
• Recall or deduce the primary cause and characteristics of each option. Is it caused by friction, a virus, or a fungus?
• Eliminate 'Athlete's foot' as it's a fungal infection causing a rash, not a thickened mass.
• Eliminate 'Plantar warts' as they are viral, painful when squeezed, and have black dots.
• Differentiate between 'Corns' and 'Callus'. Corns are painful and have a central core, while the question specifies 'painless' and 'flat'. This leaves 'Callus' as the only correct match.

Concept Tested & Keywords

• Concept Tested: Differentiation of common benign skin lesions of the foot.
• Stem keywords: flat, painless, thickened epidermis, keratotic cells, pressure, friction, palm, foot
• Lead-in keywords: is called

Question ID

QrxEMeMauN7sew9t94A8ut

Copy ID