BCC vs SCC vs Melanoma Feature Basal Cell Carcinoma (BCC) Squamous Cell Carcinoma (SCC) Malignant Melanoma Origin Basal cells of epidermis Keratinocytes of epidermis Melanocytes Incidence Most common skin cancer Second most common Less common but most deadly Malignant Potential Rarely metastasizes Low–moderate metastatic risk High metastatic potential Growth Slow-growing, locally invasive Faster-growing, may invade locally Variable; often rapid vertical growth (nodular type) Common Sites Sun-exposed: nose, eyelids, cheeks Sun-exposed: face, ears, scalp, lips Men: back; Women: legs; face/arms also Appearance Pearly, translucent nodule; telangiectasia; central ulcer “rodent ulcer” Scaly, keratotic, firm nodule; may ulcerate; cutaneous horn Pigmented lesion; ABCDE:…
Author: Dr Ben
Definition Basal Cell Carcinoma (BCC): most common non-melanoma skin cancer, originating from basal cells of the epidermis. Rarely metastasizes but can cause local tissue destruction if untreated. Epidemiology & Risk Factors Most common in fair-skinned adults >50 years. Chronic UV exposure is the main risk factor. Other risk factors: Immunosuppression Previous radiotherapy Genetic syndromes (e.g., Gorlin syndrome) Clinical Features Feature Description High-Yield Points Appearance Pearly, translucent papule or nodule with telangiectasia Often slow-growing Ulceration Central ulcer (“rodent ulcer”) Common in neglected lesions Pigmentation Can be pigmented in darker skin May mimic melanoma Common sites Face (nose, eyelids), ears, neck Sun-exposed…
Definition Malignant melanoma: aggressive melanocyte-derived skin cancer with high potential for metastasis. Most serious form of skin cancer; early detection is crucial. Epidemiology & Risk Factors Accounts for ~1–2% of skin cancers but majority of skin cancer deaths. Peak incidence: 50–60 years. Risk factors: UV exposure (especially intermittent, severe sunburns in childhood) Fair skin, light hair, blue/green eyes Multiple or atypical nevi Family history of melanoma Immunosuppression Clinical Features ABCDE Criteria (high-yield for recognition) Letter Feature Significance A Asymmetry One half unlike the other B Border Irregular, notched, poorly defined C Colour Variegated (brown, black, red, white, blue) D Diameter…
Definition Seborrheic dermatitis (SD): chronic, relapsing, inflammatory skin condition affecting sebaceous-rich areas. Characterized by erythematous, greasy, yellowish scales. Often mildly pruritic, more common in infants and adults. Epidemiology & Risk Factors Affects 2–5% of adults, more in men. Peaks: infants (“cradle cap”) and adults 30–60 years. Risk factors: Neurological disorders (Parkinson’s disease) HIV infection Stress, cold weather Oily skin or seborrhea Pathophysiology Malassezia yeast overgrowth on sebaceous skin → inflammatory response. Genetic and immune factors contribute. Sebum production promotes yeast proliferation. Clinical Features Feature Typical Location Appearance Infants Scalp (“cradle cap”), face, diaper Yellow, greasy scales, minimal erythema Adults Scalp,…
Definition Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin condition associated with pruritus, dry skin, and eczema, often linked to atopy (asthma, allergic rhinitis). Epidemiology & Risk Factors Prevalence: 10–20% in children, 2–5% in adults. Most cases begin before age 5. Family history of atopy increases risk. Triggers: irritants (soap, detergents), allergens, stress, infections (Staphylococcus aureus). Pathophysiology Skin barrier dysfunction → increased transepidermal water loss. Immune dysregulation → Th2-dominant inflammation. Pruritus-scratch cycle → worsens lesions. Clinical Features Feature Children Adults Distribution Face, scalp, extensor surfaces Flexural areas (elbows, knees), hands, eyelids Appearance Red, weeping, crusted lesions Lichenified, dry plaques…
Definition Psoriasis: chronic, immune-mediated inflammatory skin disorder characterized by well-demarcated, erythematous plaques with silvery scales. Commonly involves extensor surfaces, scalp, and sacral region. Epidemiology & Risk Factors Prevalence: 2–3% worldwide. Can affect any age; peak onset: 20–30 and 50–60 years. Triggers: trauma (Koebner phenomenon), infection (streptococcal pharyngitis → guttate psoriasis), stress, drugs (β-blockers, lithium, antimalarials, NSAIDs). Genetic predisposition: HLA-Cw6 association. Types of Psoriasis Type Features Key Points Plaque (Psoriasis vulgaris) Most common, well-demarcated erythematous plaques with silvery scales Extensor surfaces, scalp Guttate Small drop-like lesions Often post-streptococcal; acute onset Inverse Smooth, red plaques in flexures Less scaling; intertriginous areas Pustular…
Definition Urticaria (hives): transient, pruritic, erythematous wheals due to mast cell degranulation and histamine release. Duration of individual lesions: <24 hours. Key Types Type Duration Common Triggers Acute <6 weeks Foods, drugs, viral infections Chronic >6 weeks Idiopathic, autoimmune, thyroid disease Physical Triggered by physical stimuli Cold, heat, pressure, exercise (cholinergic) 💡 High-Yield Tip: Chronic urticaria is usually idiopathic or autoimmune, not allergic. Common Triggers Drugs: penicillins, NSAIDs, aspirin, opiates Foods: nuts, shellfish, eggs Infections: viral URTI, hepatitis Insect bites/stings Idiopathic Exam Trap: If urticaria occurs immediately after a drug or food, think IgE-mediated hypersensitivity → risk of anaphylaxis. Clinical…
Definition Erysipelas is an acute bacterial infection of the upper dermis and superficial lymphatics, producing a well-demarcated, raised area of inflammation. Causative Organisms Streptococcus pyogenes (Group A strep) – most common. Less commonly: Group B, C, G streptococci. 💡 Distinction: Erysipelas → almost always streptococcal. Cellulitis → can be strep or staph. Risk Factors Breaks in skin barrier (trauma, eczema, tinea pedis, ulcers). Chronic oedema, lymphatic obstruction. Diabetes, obesity. Immunosuppression. Clinical Features Abrupt onset with fever, chills, malaise. Bright red, swollen, warm plaque with raised and sharply demarcated borders. Commonly affects face and lower limbs. May see lymphangitic streaking and…
Definition Cellulitis is an acute bacterial infection of the dermis and subcutaneous tissue, usually spreading rapidly with poorly demarcated edges. Common Causative Organisms Streptococcus pyogenes (Group A strep) – most common. Staphylococcus aureus – especially when abscess or purulence is present. MRSA – consider in recurrent, hospital-acquired, or IV drug users. 💡 PLAB Gem: If cellulitis has pus, boils, or abscesses → think Staph aureus.If diffuse and spreading with lymphangitis → think Streptococcus pyogenes. Risk Factors Skin break: trauma, ulcer, surgery, insect bite. Lymphatic obstruction, venous insufficiency. Diabetes mellitus. Immunosuppression. 💡 Exam Tip: In PLAB, diabetics with foot ulcers are…
Status epilepticus (SE) is a medical emergency defined as a prolonged seizure lasting more than 5 minutes or recurrent seizures without full recovery of consciousness in between. Prompt recognition and treatment are crucial to prevent long-term neurological damage and complications, such as brain injury or death. As a PLAB 1 candidate, it’s important to be familiar with the key steps in the management of SE, as this is a high-yield topic. Classification of Status Epilepticus: Convulsive Status Epilepticus (CSE): Characterized by generalized tonic-clonic seizures. Non-convulsive Status Epilepticus (NCSE): Presenting with altered mental status or subtle seizures, often without visible motor…
Dementia is a progressive neurodegenerative syndrome marked by a decline in cognition that interferes with daily functioning. It is not a normal part of aging and deserves thorough clinical evaluation and intervention. With over 55 million people globally affected, dementia represents one of the leading causes of disability among older adults (World Health Organization). 2. Classification and Prevalence Dementia is an umbrella term comprising several subtypes, each with distinct pathology and clinical features: Subtype Estimated Prevalence Key Features Alzheimer’s Disease (AD) ~60–70% Gradual memory loss, language and visuospatial deficits Vascular Dementia (VaD) ~10–20% Stepwise decline, often post-stroke Lewy Body Dementia…
Myocardial infarction (MI), commonly known as a heart attack, occurs due to an acute obstruction of coronary blood flow, leading to ischemia and necrosis of myocardial tissue. It is a medical emergency requiring prompt recognition and intervention to reduce morbidity and mortality. This article provides a comprehensive yet clinically practical approach to MI, covering pathophysiology, ECG changes, biomarkers, and guideline-based management strategies. Further Reading: European Society of Cardiology (ESC) Guidelines on Myocardial Infarction 2. Pathophysiology of Myocardial Infarction The pathophysiology of MI follows a series of events leading to irreversible myocardial necrosis: Plaque Rupture: Disruption of an atherosclerotic plaque within…