Skin And Integument Conditions for MCCQE1 Preparation

Welcome to the comprehensive guide on Skin And Integument Conditions, tailored specifically for Canadian medical students preparing for the MCCQE1 exam. This resource is designed to align with the MCCQE1 objectives and the CanMEDS framework, focusing on the unique aspects of Canadian dermatology practice.

Table of Contents

1. Introduction to Dermatology in Canada
2. Common Skin Conditions
3. Skin Infections
4. Autoimmune Skin Disorders
5. Skin Cancers
6. Canadian Guidelines for Dermatological Care
7. Key Points to Remember for MCCQE1
8. Sample MCCQE1-Style Question
9. References

Common Skin Conditions

Acne Vulgaris

Acne is one of the most common skin conditions affecting Canadian adolescents and young adults. Understanding its pathophysiology and management is crucial for MCCQE1 preparation.

Atopic Dermatitis (Eczema)

Atopic dermatitis affects up to 17% of Canadian children and 3% of adults. Its management is a key topic for the MCCQE1 exam.

Psoriasis

Psoriasis affects approximately 1 million Canadians. Understanding its various forms and management is essential for MCCQE1 success.

Autoimmune Skin Disorders

Pemphigus Vulgaris

Pemphigus vulgaris is a rare but serious autoimmune blistering disorder that Canadian physicians should be able to recognize and manage.

Key Features:

• Flaccid blisters and erosions on skin and mucous membranes
• Positive Nikolsky sign
• Diagnosis confirmed by skin biopsy and direct immunofluorescence

Treatment:

1. Systemic corticosteroids
2. Steroid-sparing agents (e.g., azathioprine, mycophenolate mofetil)
3. Rituximab for refractory cases

Bullous Pemphigoid

Bullous pemphigoid is the most common autoimmune blistering disorder in Canada, primarily affecting older adults.

Clinical Presentation:

• Tense bullae on erythematous or normal-appearing skin
• Pruritus is often severe
• Mucous membrane involvement is less common than in pemphigus vulgaris

Canadian Management Approach:

1. Topical high-potency corticosteroids for localized disease
2. Systemic corticosteroids for widespread disease
3. Consider methotrexate or doxycycline as steroid-sparing agents

Canadian Guidelines for Dermatological Care

The Canadian Dermatology Association (CDA) provides guidelines for various skin conditions. Here are some key points relevant to MCCQE1 preparation:

1. Sun Protection: The CDA recommends daily use of broad-spectrum sunscreen with SPF 30 or higher for all Canadians, regardless of skin type or season.

2. Acne Management: The CDA emphasizes a combination approach, using topical retinoids as first-line therapy and adding benzoyl peroxide or topical antibiotics as needed.

3. Psoriasis Treatment: The CDA recommends a stepwise approach, starting with topical treatments and progressing to phototherapy and systemic agents for more severe cases.

4. Skin Cancer Screening: While there is no formal national screening program, the CDA recommends annual full-body skin examinations for high-risk individuals.

5. Eczema Care: The CDA stresses the importance of skin barrier repair with regular use of emollients, in addition to anti-inflammatory treatments.

Sample MCCQE1-Style Question

# Sample Question

A 35-year-old woman presents with a 3-week history of a pruritic rash on her trunk and extremities. She reports no recent illnesses or new medications. Physical examination reveals multiple erythematous, scaly plaques with silvery scale on the elbows, knees, and lower back. Which one of the following is the most appropriate next step in management?

- [ ] A. Prescribe a high-potency topical corticosteroid
- [ ] B. Start oral prednisone
- [ ] C. Order a skin biopsy
- [ ] D. Begin phototherapy
- [ ] E. Initiate oral methotrexate

Explanation

The correct answer is:

• A. Prescribe a high-potency topical corticosteroid

This patient's presentation is consistent with plaque psoriasis, a common chronic inflammatory skin condition. The key features supporting this diagnosis are:

1. Erythematous, scaly plaques
2. Silvery scale
3. Distribution on elbows, knees, and lower back (typical locations for psoriasis)

According to Canadian guidelines for psoriasis management, the first-line treatment for mild to moderate plaque psoriasis is topical therapy. High-potency topical corticosteroids are effective in reducing inflammation and scaling associated with psoriasis plaques.

Let's review the other options:

B. Oral prednisone is not typically recommended for psoriasis as it can lead to a severe flare upon discontinuation.

C. While a skin biopsy can confirm the diagnosis, it is usually not necessary when the clinical presentation is typical for psoriasis.

D. Phototherapy is an effective treatment for psoriasis but is typically reserved for more extensive disease or cases that don't respond to topical therapy.

E. Methotrexate is a systemic medication used for moderate to severe psoriasis that hasn't responded to topical treatments and phototherapy.

In the Canadian healthcare context, it's important to start with the least invasive, most cost-effective treatment option. Topical corticosteroids fulfill this criteria and are the appropriate first step in managing this patient's presumed psoriasis.

References

1. Canadian Dermatology Association. (2021). Position Statement on Sun Protection and Sunscreen Use. https://dermatology.ca/public-patients/sun-protection/ (opens in a new tab)

2. Lynde, C. W., et al. (2019). Canadian Practical Guide for the Treatment and Management of Atopic Dermatitis. Journal of Cutaneous Medicine and Surgery, 23(1_suppl), 3S-12S.

3. Papp, K., et al. (2016). Canadian Guidelines for the Management of Plaque Psoriasis: Overview. Journal of Cutaneous Medicine and Surgery, 20(1), 12-27.

4. BC Cancer Agency. (2021). Cancer Management Guidelines: Skin/Melanoma. http://www.bccancer.bc.ca/health-professionals/clinical-resources/cancer-management-guidelines/skin-melanoma (opens in a new tab)

5. Tan, J., et al. (2016). Acne Management for the Canadian Treating Physician. Journal of Cutaneous Medicine and Surgery, 20(3), 228-240.

6. Public Health Agency of Canada. (2020). Canadian Guidelines on Sexually Transmitted Infections. https://www.canada.ca/en/public-health/services/infectious-diseases/sexual-health-sexually-transmitted-infections/canadian-guidelines.html (opens in a new tab)