Acne vulgaris is a common inflammatory skin condition that affects adolescents and adults. It involves follicular hyperkeratinization, increased sebum production, Propionibacterium acnes colonization, and inflammation.
Pathophysiology & Epidemiology
Acne vulgaris results from a combination of increased sebum production, follicular hyperkeratinization, bacterial colonization (Propionibacterium acnes), and inflammation. It typically affects adolescents but can persist into adulthood.
Hormonal influences and genetic predisposition are key factors.
Lesions range from comedones to papules, pustules, and nodules.
Clinical Features
Comedones (open and closed), inflammatory papules, pustules, and cysts.
Distribution typically on the face, upper back, and chest.
Severe cases may lead to scarring and post-inflammatory hyperpigmentation.
Investigations
Clinical diagnosis primarily; hormonal assays (androgens, LH/FSH) in refractory cases.
Culture rarely indicated unless secondary infection is suspected.
Management
Mild to moderate: Topical retinoids, benzoyl peroxide, and antibiotics.
Severe acne: Oral antibiotics, hormonal therapy, or isotretinoin with careful monitoring.
Adjunctive therapies include proper skincare and lifestyle advice.
Complications & Prognosis
Scarring, post-inflammatory hyperpigmentation, and psychological impact.
Key Exam Points
1. Acne is multifactorial in origin.
2. Early and appropriate treatment prevents scarring.
3. Hormonal factors play a significant role.
4. Patient education on skincare is essential.
5. Severe cases may require systemic therapy.
Acne Vulgaris Quiz
1. Which bacterium is most commonly associated with acne?
A. Propionibacterium acnes
B. Staphylococcus aureus
C. Streptococcus pyogenes
D. Escherichia coli
2. What is a first-line topical treatment for mild acne?
A. Topical retinoids
B. Oral isotretinoin
C. Topical steroids
D. Topical antifungals
Atopic Dermatitis (Eczema)
Atopic dermatitis is a chronic inflammatory skin condition commonly seen in children but can persist into adulthood. It is characterized by pruritus, xerosis, and eczematous lesions in flexural areas.
Pathophysiology & Epidemiology
Atopic dermatitis involves a complex interplay between genetic factors (filaggrin mutations), immune dysregulation, and environmental triggers. It is often associated with other atopic conditions such as asthma and allergic rhinitis.
Common in early childhood; may improve or persist into adulthood.
Clinical Features
Intensely pruritic, erythematous, and lichenified plaques, often on flexural surfaces.
Associated with dry skin and excoriations.
Investigations
Diagnosis is clinical; patch testing may be indicated for contact sensitization.
Allergy testing in refractory cases.
Management
Mainstay: Regular emollient use, topical corticosteroids, and calcineurin inhibitors for maintenance.
Avoid triggers and maintain proper skin hydration.
In severe cases, systemic immunomodulators may be needed.
Complications & Prognosis
Secondary infection and post-inflammatory hyperpigmentation.
Psychosocial impact from chronic pruritus.
Key Exam Points
1. Moisturizers and trigger avoidance are crucial.
2. Topical steroids are effective for flare management.
3. Consider patch testing in refractory cases.
4. Patient education improves long-term outcomes.
5. Monitor for skin atrophy with prolonged steroid use.
Eczema Quiz
1. What is the first-line treatment for mild atopic dermatitis?
A. Emollients and topical corticosteroids
B. Systemic steroids
C. Topical antibiotics
D. Oral antihistamines alone
2. Which gene mutation is commonly associated with atopic dermatitis?
A. Filaggrin mutation
B. BRCA1 mutation
C. CFTR mutation
D. p53 mutation
Psoriasis
Psoriasis is a chronic inflammatory skin condition characterized by well-demarcated, erythematous plaques with silvery scales. It has a genetic basis and is associated with systemic comorbidities.
Pathophysiology & Epidemiology
Psoriasis results from immune dysregulation with T-cell activation and cytokine release (TNF-α, IL-17). It has a strong genetic component and can be associated with psoriatic arthritis and metabolic syndrome.
Prevalence is about 2–3% worldwide.
Clinical Features
Well-demarcated, erythematous plaques with silvery scales.
Commonly affects extensor surfaces, scalp, and lower back.
May be associated with nail changes and psoriatic arthritis.
Investigations
Primarily a clinical diagnosis; biopsy may be used in atypical cases.
Assess for comorbid conditions (e.g., metabolic syndrome, joint symptoms).
Management
Topical therapies: Corticosteroids, vitamin D analogues, and retinoids.
Phototherapy: Narrowband UVB and PUVA for moderate cases.
Systemic therapies: Methotrexate, cyclosporine, and biologic agents for severe disease.
Complications & Prognosis
Psoriatic arthritis, cardiovascular comorbidities, and psychological impact.
Key Exam Points
1. Psoriasis is an immune-mediated disorder with systemic implications.
2. Topical therapy is first-line for mild disease.
3. Biologics are effective for moderate-to-severe cases.
4. Monitor for joint involvement.
5. Patient quality of life is a key treatment outcome.
Psoriasis Quiz
1. What is the hallmark clinical feature of psoriasis?
A. Silvery scales on erythematous plaques
B. Vesicular lesions
C. Target lesions
D. Pustules only
2. Which systemic therapy is commonly used for severe psoriasis?
A. Methotrexate
B. Topical retinoids
C. Antibiotics
D. Oral antihistamines
Skin Infections
Skin infections encompass a wide range of conditions caused by bacteria, viruses, and fungi. They may present as localized or widespread infections affecting the epidermis, dermis, or subcutaneous tissues.
Pathophysiology & Epidemiology
Skin infections may be caused by bacteria (e.g., Staphylococcus aureus, Streptococcus pyogenes), viruses (e.g., herpes simplex), or fungi (e.g., dermatophytes). Factors such as trauma, impaired immunity, and poor hygiene contribute to their development.
Viral infections: herpes simplex and varicella zoster.
Clinical Features
Bacterial: Erythema, warmth, pain, swelling, and possible purulent discharge.
Fungal: Annular, scaly lesions with central clearing; nail discoloration and thickening.
Viral: Grouped vesicles on an erythematous base with potential recurrence.
Investigations
Clinical examination is often diagnostic; swab cultures for bacterial infections.
KOH preparation and fungal cultures for suspected dermatophyte infections.
Tzanck smear or PCR for viral infections when indicated.
Management
Bacterial: Topical/oral antibiotics and incision and drainage for abscesses.
Fungal: Topical antifungals (e.g., clotrimazole) or systemic agents for extensive disease.
Viral: Antiviral therapy (e.g., acyclovir) for herpes infections.
General: Maintain good hygiene and proper wound care.
Complications & Prognosis
Potential for systemic spread (sepsis) especially in immunocompromised patients.
Chronic infections, scarring, and abscess formation.
Key Exam Points
1. Differentiate pathogens based on clinical presentation.
2. Use swabs and KOH prep to confirm diagnosis.
3. Appropriate antimicrobial therapy is critical.
4. Manage complications to prevent systemic infection.
5. Emphasize hygiene and wound care.
Skin Infections Quiz
1. Which organism is most commonly responsible for impetigo?
A. Staphylococcus aureus
B. Streptococcus pyogenes
C. Pseudomonas aeruginosa
D. Escherichia coli
2. What is the first-line treatment for tinea corporis?
A. Topical antifungals
B. Oral antibiotics
C. Topical corticosteroids
D. Oral antivirals
Pigmentary Disorders
Pigmentary disorders affect skin coloration. Common conditions include vitiligo, melasma, and post-inflammatory hyperpigmentation, which may have significant cosmetic and psychological impacts.
Pathophysiology & Epidemiology
Pigmentary disorders arise from alterations in melanin production, distribution, or degradation. Vitiligo involves autoimmune destruction of melanocytes, melasma is driven by hormonal factors and UV exposure, and post-inflammatory hyperpigmentation follows skin injury.
Vitiligo affects approximately 1–2% of the population; melasma is more common in women of reproductive age.
Clinical Features
Vitiligo: Well-demarcated depigmented patches often on the face and extremities.
Melasma: Symmetrical hyperpigmented macules on the cheeks, forehead, and upper lip.
Post-inflammatory hyperpigmentation: Diffuse or localized darkening following inflammation.
Investigations
Diagnosis is primarily clinical; Wood’s lamp examination can accentuate depigmented areas in vitiligo.
Biopsy is rarely needed unless the diagnosis is uncertain.
Management
Vitiligo: Topical corticosteroids, calcineurin inhibitors, and narrowband UVB phototherapy.
Melasma: Strict photoprotection and topical agents (hydroquinone, retinoids) with possible combination therapies.
Post-inflammatory hyperpigmentation: Topical retinoids and bleaching agents; laser therapy in resistant cases.
Complications & Prognosis
Pigmentary disorders can persist long term and impact quality of life and self-esteem.
Key Exam Points
1. Wood’s lamp examination aids diagnosis.
2. Sun protection is fundamental.
3. Combination therapy often yields better results.
4. Vitiligo is autoimmune; melasma is hormonally influenced.
5. Psychological support may be needed.
Pigmentary Disorders Quiz
1. What is the typical clinical appearance of vitiligo?
A. Depigmented patches with sharp borders
B. Hyperpigmented macules
C. Erythematous plaques
D. Vesicular lesions
2. Which condition is often associated with hormonal changes and sun exposure?
A. Melasma
B. Vitiligo
C. Pityriasis rosea
D. Rosacea
Skin Cancers
Skin cancers arise from the malignant transformation of skin cells. Basal cell carcinoma (BCC) is the most common and least aggressive, squamous cell carcinoma (SCC) can metastasize, and melanoma is the most lethal due to its high metastatic potential.
Pathophysiology & Epidemiology
Skin cancers result from the malignant transformation of epidermal cells, often due to chronic UV exposure. BCC accounts for approximately 80% of cases, SCC is more aggressive, and melanoma is associated with significant mortality.
UV radiation and fair skin are major risk factors.
Early detection dramatically improves outcomes.
Clinical Features
BCC: Pearly papules with telangiectasia, sometimes with ulceration.
SCC: Scaly, indurated, or ulcerated lesions; may present with rapid growth.
Clinical examination and dermoscopy improve diagnostic accuracy.
Biopsy is the gold standard for definitive diagnosis.
Imaging is used in advanced cases for staging.
Management
BCC: Excisional surgery, Mohs micrographic surgery, or topical therapies for superficial lesions.
SCC: Surgical excision with appropriate margins; radiation therapy in selected cases.
Melanoma: Wide local excision, sentinel lymph node biopsy, and systemic therapies for metastatic disease.
Complications & Prognosis
Melanoma carries the highest risk of metastasis and mortality.
SCC may metastasize, particularly in immunosuppressed individuals.
Key Exam Points
1. Early detection through dermoscopy and biopsy is crucial.
2. Treatment modality varies with cancer type and stage.
3. UV protection is essential in prevention.
4. Monitor high-risk patients closely.
5. Multidisciplinary management is often required.
Skin Cancers Quiz
1. Which skin cancer is characterized by pearly papules with telangiectasia?
A. Basal cell carcinoma
B. Squamous cell carcinoma
C. Melanoma
D. Merkel cell carcinoma
2. What does the “ABCDE” rule in melanoma stand for?
A. Asymmetry, Border, Color, Diameter, Evolving
B. Atypical, Bleeding, Color, Diameter, Elevation
C. Asymptomatic, Border, Congestion, Duration, Erythema
D. Atypical, Border, Crusting, Diameter, Evolving
Hair & Nail Disorders
Hair and nail disorders include conditions such as alopecia, onychomycosis, and nail psoriasis. These conditions can have significant cosmetic and psychological impacts.
Pathophysiology & Epidemiology
Hair and nail disorders may result from genetic, infectious, inflammatory, or traumatic causes. Conditions such as alopecia areata are autoimmune, whereas onychomycosis is typically fungal in origin.
Alopecia areata, androgenetic alopecia, and telogen effluvium are common causes of hair loss.
Nail disorders include fungal infections, psoriasis, and brittle nails.
Clinical Features
Alopecia: Patchy, non-scarring hair loss with exclamation mark hairs in alopecia areata.
Onychomycosis: Discoloration, thickening, and crumbling of nails.
Nail psoriasis: Pitting, onycholysis, and subungual hyperkeratosis.
Investigations
Clinical examination is key; KOH preparation and fungal cultures for suspected onychomycosis.
Trichoscopy can aid in diagnosing hair disorders.
Nail biopsy in atypical or refractory cases.
Management
Alopecia areata: Topical or intralesional corticosteroids; consider minoxidil for androgenetic alopecia.
Onychomycosis: Topical or systemic antifungal agents.
Nail psoriasis: Topical therapies; systemic agents for severe cases.
Complications & Prognosis
Chronic hair loss may cause psychological distress.
Untreated onychomycosis can lead to secondary bacterial infections.
Key Exam Points
1. Trichoscopy is useful for hair disorders.
2. Fungal cultures confirm onychomycosis.
3. Early treatment can prevent permanent hair loss and nail dystrophy.
4. Topical therapies are first-line for nail disorders.
5. Psychological support is often important.
Hair & Nail Disorders Quiz
1. Which condition is characterized by patchy, non-scarring hair loss?
A. Alopecia areata
B. Androgenetic alopecia
C. Telogen effluvium
D. Traction alopecia
2. What is the first-line treatment for onychomycosis?
A. Oral antifungals
B. Topical corticosteroids
C. Oral antibiotics
D. Topical retinoids
Inflammatory Dermatoses
Inflammatory dermatoses include a variety of conditions caused by external triggers or intrinsic inflammation. Common examples include contact dermatitis, seborrheic dermatitis, and rosacea.
Pathophysiology & Epidemiology
Inflammatory dermatoses result from immune-mediated reactions, irritant exposure, or both. Contact dermatitis is triggered by allergens or irritants, seborrheic dermatitis is associated with Malassezia yeasts and sebum production, and rosacea involves vascular and inflammatory dysregulation.
These conditions affect patients of various ages and may be chronic or relapsing.
Clinical Features
Contact dermatitis: Pruritic, erythematous, and vesicular lesions localized to areas of exposure.
Seborrheic dermatitis: Greasy scales and erythema on the scalp, face, and chest.
Rosacea: Flushing, persistent facial erythema, telangiectasia, and papulopustular lesions.
Investigations
Diagnosis is mainly clinical; patch testing is useful in suspected allergic contact dermatitis.
Skin scrapings may be performed when a fungal contribution is suspected in seborrheic dermatitis.
Management
General measures include trigger avoidance and regular use of emollients.
Topical corticosteroids for acute flares.
Seborrheic dermatitis: Topical antifungals and low-potency steroids.
Rosacea: Topical metronidazole or ivermectin and lifestyle modifications.
Complications & Prognosis
Chronic inflammation may lead to lichenification, hyperpigmentation, and secondary infections.
Key Exam Points
1. Trigger identification and avoidance are crucial.
2. Topical corticosteroids are effective for acute management but require careful use.
3. Seborrheic dermatitis may benefit from antifungal therapy.
4. Rosacea is managed with a multifaceted approach.
5. Early treatment minimizes long-term changes.
Inflammatory Dermatoses Quiz
1. Which condition is characterized by greasy scales on the scalp?
A. Seborrheic dermatitis
B. Psoriasis
C. Atopic dermatitis
D. Lichen planus
2. What is the first-line treatment for allergic contact dermatitis?
A. Topical corticosteroids
B. Oral antibiotics
C. Antifungals
D. Retinoids
Autoimmune Dermatoses
Autoimmune dermatoses, such as cutaneous lupus erythematosus, dermatomyositis, and scleroderma, involve an aberrant immune response against skin components. They often have systemic associations and require a multidisciplinary approach.
Pathophysiology & Epidemiology
Autoimmune dermatoses occur when the immune system attacks normal skin tissues. Cutaneous lupus, dermatomyositis, and scleroderma have distinct clinical features, serological markers, and may be associated with systemic disease.
Genetic predisposition and environmental triggers play key roles.
Immunosuppressive agents (methotrexate, azathioprine) for steroid-sparing effect.
Photoprotection is essential in lupus.
Multidisciplinary care is often required.
Complications & Prognosis
Potential systemic involvement, organ damage, and chronic morbidity.
Key Exam Points
1. Autoimmune dermatoses require long-term, multidisciplinary management.
2. Autoantibody testing is critical for diagnosis.
3. Photoprotection and early treatment improve outcomes.
4. Monitor for systemic involvement.
5. Tailor immunosuppressive therapy to disease severity.
Autoimmune Dermatoses Quiz
1. Which rash is characteristic of dermatomyositis?
A. Heliotrope rash
B. Malar rash
C. Psoriatic plaque
D. Vesicular rash
2. What is the first-line systemic treatment for severe cutaneous lupus?
A. Systemic corticosteroids
B. Topical retinoids
C. Oral antibiotics
D. Antifungals
Occupational Dermatoses
Occupational dermatoses result from repeated exposure to irritants or allergens in the workplace. They include irritant and allergic contact dermatitis as well as photodermatoses.
Pathophysiology & Epidemiology
Occupational dermatoses occur due to repetitive exposure to chemicals, solvents, and physical agents in the workplace. Irritant contact dermatitis is the most common, followed by allergic contact dermatitis.
Prevention is key and relies on protective equipment and workplace safety measures.
Clinical Features
Localized erythema, scaling, vesiculation at exposure sites.
Chronic cases may show lichenification and hyperpigmentation.
Investigations
Detailed occupational history and clinical examination.
Patch testing to identify specific allergens.
Management
Avoidance of the causative agent and use of personal protective equipment.
Topical corticosteroids and emollients for symptomatic relief.
Workplace modifications and patient education are essential.
Complications & Prognosis
Chronic dermatitis, scarring, and persistent hyperpigmentation.
Key Exam Points
1. A thorough work history is vital in diagnosing occupational dermatoses.
2. Patch testing confirms allergen sensitivity.
3. Protective measures are crucial for prevention.
4. Early intervention minimizes chronic changes.
5. Multidisciplinary management can improve outcomes.
Occupational Dermatoses Quiz
1. What is the most common form of occupational dermatitis?
A. Irritant contact dermatitis
B. Allergic contact dermatitis
C. Photodermatitis
D. Atopic dermatitis
2. What is a key preventive strategy for occupational dermatoses?
