Dermatology - Key Concepts and Clinical Features

These flashcards cover key concepts from the dermatology lecture focusing on clinical features, pathophysiology, treatments, and conditions related to skin health.

What are the clinical features of melanoma characterized by the ABCDE criteria?

Asymmetry, Border irregularities, Color variegation, Diameter ≥6 mm, Evolving lesions.

What causes tuberous sclerosis complex?

Mutation in TSC1 or TSC2 gene, inherited or de novo, autosomal dominant.

What are the dermatologic features of tuberous sclerosis complex?

Ash-leaf spots, angiofibromas of the malar region, shagreen patches.

Which brain conditions are associated with tuberous sclerosis complex?

CNS lesions, epilepsy (infantile spasms), intellectual disability, autism.

What are the cardiovascular manifestations of tuberous sclerosis complex?

Rhabdomyomas.

What renal conditions are associated with tuberous sclerosis complex?

Angiomyolipomas.

What is the clinical presentation of pemphigus vulgaris?

Painful, flaccid bullae that lead to erosions.

What is the clinical presentation of bullous pemphigoid?

Large, tense blisters on normal or erythematous skin, often itchy.

What is the main difference in age of onset between pemphigus vulgaris and bullous pemphigoid?

Pemphigus vulgaris presents at ages 40-60, bullous pemphigoid typically presents at age > 60.

What are the histological and IF findings in pemphigus vulgaris?

Intraepidermal cleavage and net-like intercellular IgG against desmosomes.

What are the histological and IF findings in bullous pemphigoid?

Subepidermal cleavage, linear IgG against hemidesmosomes along the basement membrane.

What risk factors are associated with basal cell carcinoma?

Sun/ultraviolet exposure, fair skin, ionizing radiation.

Describe the clinical features of basal cell carcinoma.

Skin-colored, pearly nodule with possible rolled borders and telangiectatic vessels. Can have central ulceration.

What are the first-line treatments for basal cell carcinoma?

Surgical excision with 4-mm margins or Mohs micrographic surgery for high-risk tumors.

Second-line: topical fluorouracil, topical imiquimod, C and E for low-risk tumors only.

What skin conditions are associated with insulin resistance?

Acanthosis nigricans. Multiple skin tags.

What skin conditions are associated with GI malignancy?

Acanthosis nigricans. Explosive onset multiple itchy seborrheic keratoses.

What skin conditions are associated with pregnancy?

Changes such as melasma, striae gravidarum, and pruritic urticarial papules and plaques. Multiple skin tags.

What skin conditions are associated with hepatitis C?

Lichen planus. Porphyria cutanea tarda. Cutaneous leukocytoclastic vasculitis (palpable purpura) secondary to cryoglobulinemia.

What skin conditions are associated with celiac disease?

Dermatitis herpetiformis.

What skin conditions are associated with HIV infection?

Sudden onset severe psoriasis. Recurrent herpes zoster. Disseminated molluscum contagiosum. Severe seborrheic dermatitis.

What skin conditions are associated with IBD?

Pyoderma gangrenosum.

What is the pathogenesis of seborrheic dermatitis? What are the clinical features? What are the risk factors?

Seborrheic dermatitis is a chronic inflammatory skin condition characterized by greasy, scaly patches on the scalp, face, and other oily areas. It is associated with Malassezia yeast overgrowth, and risk factors include stress, oily skin, and certain neurological disorders. The pathogenesis involves an abnormal immune response to Malassezia, leading to inflammation. Clinical features include red, itchy patches with a yellowish scaling. Risk factors include CNS disease and HIV.

What is the treatment of seborrheic dermatitis?

The treatment of seborrheic dermatitis typically involves the use of medicated shampoos containing antifungal agents such as ketoconazole, selenium sulfide, or zinc pyrithione, topical corticosteroids to reduce inflammation, and lifestyle modifications to manage triggers. In severe cases, systemic treatments may be considered.

What is the pathogenesis of hidradenitis suppurativa? What are the clinical features? What are the risk factors?

Hidradenitis suppurativa is a chronic skin condition characterized by painful, inflamed nodules and abscesses in intertriginous areas, often resulting in scarring. The pathogenesis involves follicular occlusion and an abnormal immune response, with clinical features including recurrent lumps, pus drainage, and tunneling under the skin. Risk factors include obesity, smoking, and family history.

What is the treatment of hidradenitis suppurativa?

Mild: topical clindamycin.

Moderate: oral tetracycline.

Severe: TNF-alpha inhibitors (adalimumab), surgical excision.

What are the complications of hidradenitis suppurativa?

Depression, suicide. Squamous cell carcinoma of skin.

What skin condition presents with painful, nodular lesions and possible sine-tracts? Usually in armpits.

Hidradenitis suppurativa.

What is acute palmoplantar eczema/dyshidrotic eczema?

A skin condition characterized by itchy, blistering vesicles and bullae on the palms of the hands and soles of the feet, often triggered by stress or irritants. Complications include desquamation, chronic dermatitis, and secondary infection.

What is the diagnostic criteria for acute palmoplantar eczema/dyshidrotic eczema?

Clinical features. Biopsy is not needed, but it does show intraepidermal spongiosis and lymphocytic infiltrate.

What is the treatment of acute palmoplantar eczema/dyshidrotic eczema?

Topical emollients, high potency topical corticosteroids.

What are the main causes of drug-induced acne?

Common triggers include glucocorticoids, androgens, immunomodulators (azathioprine, EGFR inhibitors), anticonvulsants (phenytoin), antipsychotics, anti-TB drugs (isoniazid).

What is the presentation of drug-induced acne?

Monomorphic papules or pustules. NO comedones/cysts/nodules.

What are typical features of acne vulgaris?

Presence of comedones, inflamed papules, pustules, and nodules.

What clinical findings are characteristic of acute urticaria?

Pruritic, erythematous plaques, also known as wheals, which each last less than 24 hours.

What triggers the release of histamine leading to urticaria?

Mast cell activation.

What is the typical presentation of erythema nodosum?

Tender, indurated, erythematous nodules usually located on the anterior legs.

What is the common name for erythema multiforme?

Target lesions related to HSV infection.

What is the characteristic appearance of lichen planus lesions?

Pruritic, purple or pink polygonal papules and plaques, often with Wickham striae.

What is the distinct characteristic of contact dermatitis?

It results from a type IV hypersensitivity reaction.

What kind of skin findings are common in psoriasis?

Chronic, well-demarcated scaly plaques.

What is the key feature of seborrheic dermatitis in adults?

Erythematous, pruritic plaques with greasy scales primarily on the scalp, face, and trunk.

What is the typical management for vitiligo?

Topical corticosteroids for limited disease; oral corticosteroids and phototherapy for extensive disease.

What are the features of actinic keratosis?

Erythematous, scaly papules; rough plaques typically found in sun-exposed areas.

How does malignant melanoma typically evolve?

Changes in size, shape, or color of the lesion; presence of new lesions.

What differentiates eczema from other skin conditions?

It involves chronic itching and inflammatory changes with skin barrier dysfunction.

What factor increases the risk for squamous cell carcinoma?

Sun exposure and chronic wounds.

Which disease presents with target lesions and can be triggered by infections like HSV?

Erythema multiforme.

What are the common treatments for rosacea?

Topical metronidazole, azelaic acid, and oral tetracyclines.

What are ineffective measures for preventing tinea cruris?

Using nystatin, as it is ineffective against dermatophyte infections.

What is the most common clinical feature of lichen planus?

The appearance of polygonal papules with a purple color.

What specifies the involvement of acne mechanica?

The presence of acneiform eruptions caused by pressure-related trauma.

What are the complications of hidradenitis suppurativa?

Chronic lesions and possible progression to squamous cell carcinoma.

How does drug-induced acne typically present?

Monomorphic papules or pustules with a lack of comedones.

What type of dermatitis results from poison ivy exposure?

Allergic contact dermatitis.

What is the common presentation for cutaneous leukocytoclastic vasculitis?

Palpable purpura secondary to cryoglobulinemia.

How is keratosis pilaris diagnosed?

Diagnosis is primarily based on clinical findings.

What initial treatment is used for eczema?

Topical emollients and high-potency corticosteroids.

What indicates the need for a biopsy in skin lesions?

Lesions that exhibit features of possible SCC.

What feature is commonly associated with severe seborrheic dermatitis?

Itchy and eruptive formation of seborrheic keratoses.

What clinical presentation is indicative of dermatomyositis?

Heliotrope rash and Gottron's papules.

What is the clinical feature of erythema migrans?

Characteristic expanding bullseye rash associated with Lyme disease.

What condition is characterized by painful, purulent ulcers with a violaceous border?

Pyoderma gangrenosum.

What is the primary treatment for acute urticaria?

Second-generation H₁ antihistamines.

In what area of the skin do bullous pemphigoid lesions typically form?

Subepidermally, affecting areas like the axillae and groin.

What are the common medications associated with acne vulgaris treatment?

Topical retinoids, benzoyl peroxide, and oral antibiotics.

What are the primary risk factors for developing squamous cell carcinoma?

Chronic sun exposure, immunosuppression, and exposure to ionizing radiation.

How does herpes simplex virus infection typically manifest on the skin?

Localized vesicles and pustules that are painful.

Which type of eczema is known for deep-seated vesicles on palms and soles?

Dyshidrotic eczema.

What factors characterize the chronic phase of eczema?

Lichenification and scaling of the affected regions.

What skin finding is typical in patients with HIV/AIDS?

Disseminated molluscum contagiosum and recurrent herpes zoster.

What is the first-line therapy for seborrheic dermatitis?

Topical antifungals or low-potency topical corticosteroids.

What is the defining characteristic of contact urticaria?

Immediate hypersensitivity reaction following skin exposure to an allergen.

What differentiates inflammatory acne from comedonal acne?

Inflammatory acne involves inflamed papules and pustules, while comedonal acne includes closed or open comedones.

What are the types of acne vulgars?

Comedonal acne, inflammatory acne, nodular/cystic acne.

How do we treat comedonal acne?

Topical retinoids, salicylic acid, azelaic acid, glycolic acid.

How do we treat inflammatory acne?

Mild: topical retinoids + benzoyl peroxide.

Moderate: Add topical antibiotics (clindamycin, erythromycin).

Severe: Add oral antibiotics.

How do we treat nodular/cystic acne?

Moderate: topical retinoid + benzoyl peroxide + topical antibiotics.

Severe: add oral antibiotics.

Unresponsive and severe: oral isotretinoin.

What does herpetic whitlow look like?

Localized vesicles and pustules. Painful lesions on one hand.

How is herpetic whitlow treated?

Treatment is primarily supportive, including antiviral medications such as acyclovir. Topical analgesics may also be used to alleviate pain.

What does nummular eczema look like?

Circular, coin-shaped patches with dry, scaly skin. Usually itchy and may ooze. On lower extremities.

How is nummular eczema treated?

Treatment focuses on moisturizing the skin, using topical corticosteroids to reduce inflammation, and avoiding irritants.

What does psoriasis look like?

Characterized by well-demarcated scaly plaques: red, raised patches covered with silvery-white scales. Often found on elbows, knees, and scalp.

How is psoriasis treated?

Treatment includes topical corticosteroids, vitamin D analogs, phototherapy, and systemic treatments such as biologics for moderate to severe cases.

What does scabies look like?

Small, red bumps and blisters with intense itching. Commonly found between fingers, wrists, and in skin folds (web spaces and flexural surfaces). Caused by mites burrowing into the skin, leading to a rash and secondary infections. Severe itching at night.

How is scabies treated?

Treatment typically involves topical permethrin or oral ivermectin to eliminate mites. It is important to treat close contacts and wash clothing and bedding to prevent re-infestation.

What does tinea manuum look like?

Tinea manuum, or ringworm of the hand, appears as red, scaly patches with well-defined edges. It may cause itching and is often associated with similar lesions on other parts of the body. The rash can also present with circular, ring-like lesions that may have clear centers and can spread to other areas of the skin.

How is tinea manuum treated?

Treatment usually involves topical antifungal creams, such as clotrimazole or terbinafine, applied to the affected areas. In more severe cases, oral antifungals may be prescribed, along with measures to prevent reinfection.

What does tinea pedis look like?

Tinea pedis, commonly known as athlete's foot, presents as red, itchy, and scaly lesions between the toes or on the soles of the feet. It may also cause cracking, peeling skin, and blisters.

How is tinea pedis treated?

Treatment typically includes topical antifungal agents like miconazole or clotrimazole. In more severe cases, oral antifungals may be necessary, along with proper foot hygiene and measures to keep the feet dry.

What lesion presentation is associated with actinic keratosis?

Scaly, erythematous papules that can develop into squamous cell carcinoma.

How is actinic keratosis treated?

Treatment for actinic keratosis includes cryotherapy, topical medications like 5-fluorouracil, and photodynamic therapy. Surgical options may be considered for more extensive lesions.

What are the different types of rosacea?

Rosacea can be classified into several types, including erythematotelangiectatic rosacea, papulopustular rosacea, phymatous rosacea, and ocular rosacea. Each type presents unique symptoms and requires different management strategies.

What is erythematotelangiectatic rosacea? How is it treated?

Erythematotelangiectatic rosacea is characterized by persistent redness, flushing, and visible blood vessels on the face. Treatment may include topical brimonidine and laser/intense pulsed light therapy.

What is papulopustular rosacea? How is it treated?

Papulopustular rosacea is characterized by red, inflamed papules and pustules typically found on the face. Treatment options include first line: topical metronidazole, azelaic acid, ivermectin; second-line: oral tetracyclines.

What is phymatous rosacea? How is it treated?

Phymatous rosacea is characterized by thickened skin, irregular surface nodularity, and often affects the nose, leading to rhinophyma. Treatment may involve oral isotretinoin and laser therapy/surgery.

What is ocular rosacea? How is it treated?

Ocular rosacea is characterized by eye irritation, redness, and inflammation of the eyelids and conjunctiva. Treatment typically involves lid scrubs, ocular lubricants, topical or systemic antibiotics (metronidazole, macrolides).

What is bullous impetigo? Who does it affect? Where does it affect?

Skin infection caused by Staphylococcus aureus. Rapidly enlarging vesicles and bullae, which rupture to exudates and crusts. Condition is most common in children. Only in adults if immunocompromised. It primarily affects the face, neck, and trunk.

What is bullous pemphigoid? Who does it affect? Where does it affect?

Bullous pemphigoid is an autoimmune blistering disorder that causes large, tense blisters on the skin. It primarily affects elderly > 60 yo individuals, usually on the areas of the abdomen, groin, axillae, and medial thighs. Treatment may involve systemic corticosteroids and immunosuppressants.

What is sporotrichosis? Who does it affect? Where does it affect?

Sporotrichosis is a fungal infection caused by the fungus $Sporothrix schenckii$. It commonly affects gardeners and those who handle soil or plant materials, typically involving the skin, especially on the hands and forearms, but can disseminate to other parts of the body. It presents with ulcerating, pustular nodules at the site of inoculation (usually on 1 hand). The patients are asymptomatic.

What is vitiligo? Pathogenesis, distribution, what it looks like.

Vitiligo is a skin condition characterized by the loss of melanocytes, leading to depigmented patches on the skin. It can affect any area of the body, often seen on the face, hands, and around body openings. The patches typically appear lighter than the surrounding skin and may vary in size and shape. It is thought to be autoimmune in nature, with genetic and environmental factors contributing to its development, commonly affecting individuals of all ages.