Lecture 6 Part 1

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of nevus is first in the natural progression of a mole?

Junctional nevus (correct)

Compound nevus

Dermal nevus

Atypical nevus

Which type of nevus is characterized by being flat and brown?

Dermal nevus

Compound nevus

Junctional nevus (correct)

Atypical nevus

What distinct feature differentiates atypical nevi from typical nevi?

They have irregular borders and shapes. (correct)

They contain only one color.

They are round and have smooth borders.

They are always skin-colored.

What is the term for moles that are raised and skin-colored?

Dermal nevi Signup and view all the answers

How many major types of moles are described?

Four major types Signup and view all the answers

Which feature is NOT characteristic of a typical nevus?

Irregular shape Signup and view all the answers

What common feature do junctional and compound nevi share?

Both have melanocyte proliferation at the junction. Signup and view all the answers

Which feature indicates that a nevus is atypical?

It has at least two different tones of color. Signup and view all the answers

What is a characteristic appearance of atypical nevi?

Raised, darker center with flat, lighter periphery Signup and view all the answers

Which area does acne involvement typically indicate more severe disease?

Chest and back Signup and view all the answers

What is the size of a nodule in acne?

1-2 cm Signup and view all the answers

Which type of lesion is characterized by a small (1-2 mm) flesh-colored papule?

Closed comedone Signup and view all the answers

What is a primary pathogenesis factor in the development of acne?

Abnormal cohesiveness of keratinocytes Signup and view all the answers

Which lesion is NOT classified as one of the six distinct types of acne lesions?

Vesicle Signup and view all the answers

What does the presence of chin and/or jawline lesions in women generally indicate?

Hormone-induced acne Signup and view all the answers

Which type of acne scar is characterized by a narrow, deep depression?

Ice pick scar Signup and view all the answers

What is the primary theory regarding the cause of darkening and thickening associated with acanthosis nigricans?

Insulin-like growth factor receptor activation Signup and view all the answers

What is considered the most effective treatment for acanthosis nigricans in obese individuals?

Weight loss Signup and view all the answers

In evaluating a patient with acanthosis nigricans, what aspect is crucial to investigate for underlying causes?

Fasting blood glucose levels Signup and view all the answers

Which underlying malignancy is classically associated with acanthosis nigricans?

Gastric adenocarcinoma Signup and view all the answers

When should a patient with rapidly developing acanthosis nigricans be evaluated for malignancies?

If it involves the peri-oral area Signup and view all the answers

What is the term used for the lesion that is not visible to the naked eye and occurs due to the accumulation of sebaceous secretions within the follicle?

Microcomedone Signup and view all the answers

What is the main reason for the dark color of an open comedone (blackhead)?

Oxidized sebaceous material Signup and view all the answers

What type of lesion forms from inflammation in the superficial portion of the hair follicle?

Pustule Signup and view all the answers

Which bacterial species is identified as a source of inflammatory stimuli in acne?

Propionibacterium acnes Signup and view all the answers

What consequence occurs when a papule ruptures and releases its contents into the dermis?

Massive inflammatory response leading to a nodule Signup and view all the answers

In what manner do androgenic hormones contribute to the development of acne?

Enhance sebaceous gland activity Signup and view all the answers

The treatment of acne aimed at patients with predominantly open and closed comedones focuses on which of the following?

Targeting abnormal keratinocyte cohesion Signup and view all the answers

What happens to sebaceous production when the follicle is compressed by the accumulation of material?

It completely stops Signup and view all the answers

What is the typical initial manifestation of Pityriasis Rosea in over half of the cases?

Herald patch Signup and view all the answers

Which of the following describes the appearance of the plaques in Pityriasis Rosea?

Oval and oriented in a Christmas Tree pattern Signup and view all the answers

What is a common cause of Keratosis Pilaris?

Atopic dermatitis Signup and view all the answers

What skincare treatments are typically recommended for Keratosis Pilaris?

Keratolytic moisturizers and retinoids Signup and view all the answers

What is a characteristic presentation of Acanthosis Nigricans?

Darkening and thickening of skin Signup and view all the answers

What is typically effective for treating associated pruritus in Pityriasis Rosea?

Topical steroids Signup and view all the answers

Which populations are most commonly affected by Pityriasis Rosea?

Teenagers and young adults Signup and view all the answers

What is the typical duration for spontaneous resolution of Pityriasis Rosea?

6-8 weeks Signup and view all the answers

What is the primary effect of isotretinoin in acne treatment?

It permanently decreases keratinocyte cohesion and sebaceous gland activity. Signup and view all the answers

What should be considered when choosing oral contraceptives for acne treatment?

Synthetic progestins and their androgenic activity vary. Signup and view all the answers

Which medication is known for its non-specific anti-inflammatory activity and for reducing P.acnes counts?

Doxycycline Signup and view all the answers

What percentage of patients is expected to be 'cured' of their acne after a course of isotretinoin?

70 - 80% Signup and view all the answers

Why is compliance considered a critical factor in acne treatment?

Non-compliance is the leading cause of treatment failure. Signup and view all the answers

Which treatment is specifically designed to reduce P.acnes populations?

Topical antibiotics Signup and view all the answers

What is one of the common side effects of topical regimens that include retinoids?

Irritation Signup and view all the answers

How long is the typical treatment course for isotretinoin?

5-6 months Signup and view all the answers

Study Notes

Moles (Melanocytic Nevi)

Moles are common, with most people having at least one.
Moles can be junctional, compound, dermal, or atypical.
Junctional nevi are flat and brown, located at the epidermis-dermis junction.
Compound nevi are raised and brown, with melanocytes at the epidermis-dermis junction and in the dermis.
Dermal nevi are raised and skin-colored, with melanocytes only in the dermis.
Atypical nevi are different from compound nevi clinically and histologically; they often have irregular boundaries, irregular shape, mixed colors, and a larger size (>6mm).

Other Nevi

Halo Nevus: A mole with a white rim around it, potentially linked to an immune response, melanoma, or vitiligo. Full body exam is recommended.
Nevus Spilus: Congenital light tan macule with dark speckles; often removed for cosmetic reasons.
Blue Nevus: Homogenous blue macule; typically flat, small, and symmetrical. Evaluation and removal if atypical features (e.g., irregular borders, non-homogenous color) are present.
Ephelides (Freckles): Small brown macules on sun-exposed areas, decreasing in presence with decreased sun exposure.
Lentigines (Liver Spots): Larger, darker spots than freckles; do not fade with decreased sun exposure.

Acne

Acne is common, affecting over 50% of the population without impacting health.
Acne primarily begins with puberty but can emerge earlier.
It typically affects the face, chest, and back, with the chin/jawline in women indicative of hormonal involvement.
Acne has different lesion types: open comedones (blackheads), closed comedones (whiteheads), papules, pustules, nodules, and scars.

Pityriasis Rosea (PR)

Common in teens and young adults, typically starts with a herald patch (oval, red-brown plaque).
Within days to weeks, more similar-shaped plaques appear across the trunk.
The distribution of plaques is often in a "Christmas Tree" pattern.
Self-resolves in 6-8 weeks, but occasionally persists longer.

Keratosis Pilaris (KP)

Common, characterized by rough, red papules at hair follicle openings.
Usually on the upper arms and anterior thighs.
Treated with keratolytic moisturizers or retinoids.

Acanthosis Nigricans (AN)

Characterized by darkening and thickening of skin folds.
Often linked to obesity, glucose intolerance, and insulin resistance.
May be associated with underlying malignancies.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on skin lesions, specifically focusing on moles (nevi) and acne types. This quiz covers various characteristics, classifications, and pathogenesis related to these common dermatological concerns. Perfect for students in dermatology or health sciences.