UPSC MainsMEDICAL-SCIENCE-PAPER-II20225 Marks
Q26.

What are the four 'P's used to describe clinical manifestation of lichen planus ?

How to Approach

This question requires a concise and accurate recall of a key clinical descriptor used in dermatology, specifically relating to Lichen Planus. The answer should directly state the four 'P's and briefly explain each. A structured approach listing each 'P' with its description is ideal. Avoid going into extensive details about Lichen Planus itself, as the question focuses solely on the four 'P's.

Model Answer

0 min read

Introduction

Lichen planus is a chronic inflammatory condition affecting the skin, mucous membranes, hair, and nails. Accurate clinical assessment is crucial for diagnosis and management. A helpful mnemonic used to remember the key clinical manifestations of Lichen Planus is the “Four P’s”. These characteristics aid in differentiating it from other dermatological conditions and guide appropriate treatment strategies. Understanding these features is fundamental for any medical practitioner, particularly in dermatology.

The Four ‘P’s of Lichen Planus

The four ‘P’s used to describe the clinical manifestation of lichen planus are:

1. Papules

These are small, raised, solid bumps on the skin. They are typically 2-5mm in diameter and are often numerous. The papules are a hallmark of Lichen Planus and are frequently found on the flexural surfaces of the wrists and ankles, as well as the lower back. They can be skin-colored, reddish-purple, or even brownish.

2. Pruritus

This refers to intense itching. Pruritus is a very common symptom in Lichen Planus and can be debilitating for patients. The itching can be localized to the areas affected by the rash or more generalized. It often worsens at night and can lead to excoriations (scratch marks) due to constant scratching.

3. Plaques

As the papules coalesce, they can form larger, flat-topped, slightly raised lesions called plaques. These plaques are typically polygonal in shape and can be more widespread than the individual papules. They often exhibit a violaceous (purple) hue and can be scaly.

4. Pigmentation

Post-inflammatory hyperpigmentation is a common sequela of Lichen Planus, particularly after the lesions have resolved. This means that the skin in the affected areas becomes darker than the surrounding skin. Hyperpigmentation can persist for months or even years after the active inflammation has subsided. Less commonly, hypopigmentation can occur.

It’s important to note that not all patients will present with all four ‘P’s simultaneously. The clinical presentation can vary depending on the subtype of Lichen Planus (e.g., classic, erosive, pigmentosus).

Conclusion

In summary, the four ‘P’s – Papules, Pruritus, Plaques, and Pigmentation – provide a useful framework for recognizing the clinical features of Lichen Planus. Recognizing these characteristics is essential for accurate diagnosis and initiating appropriate management strategies to alleviate symptoms and improve the patient’s quality of life. A thorough clinical examination, coupled with histopathological confirmation, remains crucial for definitive diagnosis.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Polygonal
Having many angles; a shape with multiple sides, often referring to the shape of plaques in Lichen Planus.
Post-inflammatory Hyperpigmentation
Darkening of the skin following inflammation, a common occurrence after Lichen Planus lesions resolve.

Key Statistics

Lichen planus affects approximately 0.1-0.2% of the general population.

Source: American Academy of Dermatology (Knowledge cutoff: 2023)

Approximately 70% of patients with Lichen Planus experience pruritus.

Source: Journal of the American Academy of Dermatology (Knowledge cutoff: 2023)

Examples

Oral Lichen Planus

A 45-year-old female presents with painful ulcers in her mouth, accompanied by a lacy, white pattern on her buccal mucosa. Biopsy confirms a diagnosis of oral lichen planus, demonstrating the involvement of mucous membranes.

Frequently Asked Questions

Is Lichen Planus contagious?

No, Lichen Planus is not contagious. It is an autoimmune condition, meaning it is caused by the body's immune system attacking its own tissues.

Topics Covered

MedicineDermatologySkin DiseaseInflammationDiagnosis