Dermatology
Browse 77 topics in dermatology, including presentations, diagnoses, procedures, tools, and exam links.
Specialty map
Use the filters below to move between emergency clusters, core pathways, exam topics, procedures, and the most relevant clinical atlas pages.
Acne Vulgaris
While often dismissed as a "rite of passage," acne carries a significant psychological burden, with rates of depression and suicidal ideation comparable to chronic systemic diseases like epilepsy or diabetes....
Acute Urticaria in Adults
Acute urticaria is a common dermatological condition characterized by the sudden onset of transient, pruritic, erythemat... MRCP exam preparation.
Alopecia
Hair loss presents in diverse patterns, from well-defined patches to diffuse thinning or total baldness. The most common types—androgenetic alopecia, alopecia areata, and telogen effluvium—account for the majority of...
Alopecia Areata (Adult)
Alopecia areata (AA) is a common, T-cell mediated autoimmune disorder characterised by non-scarring hair loss manifesting as well-demarcated, round or oval patches of complete alopecia. The condition affects...
Anthrax
Bacillus anthracis is classified as a Category A bioterrorism agent by the CDC due to its stability as spores (surviving decades in soil), ease of dissemination, high mortality potential, and capacity to cause public...
Atopic Eczema
The underlying pathophysiology involves a complex interplay of epidermal barrier dysfunction (commonly associated with filaggrin mutations), type 2 immune dysregulation (Th2-predominant response with IL-4, IL-13,...
Atopic Eczema (Adult)
Atopic eczema (atopic dermatitis, AD) is a chronic, relapsing inflammatory skin condition characterised by intense pruritus, xerosis, and eczematous lesions with age-dependent distribution patterns. It affects 15-20%...
Balanitis
Key Facts Prevalence : 3% of boys; 11% of adult men; 12-14% of men attending GUM clinics Most common causes : Candida albicans (30-35%), poor hygiene/irritant dermatitis (25-30%), bacterial (15-20%), dermatoses...
Basal Cell Carcinoma
While BCC has an exceptionally low metastatic rate (less than 0.1%), it remains a significant clinical challenge due to its high incidence, potential for local invasion and tissue destruction, and substantial...
Behçet's Disease
Behçet's disease (BD) is a chronic, relapsing, multisystem inflammatory disorder characterised by recurrent oral and gen... MRCP exam preparation.
Blepharitis (Adult)
Blepharitis is a chronic inflammatory condition affecting the eyelid margins, representing one of the most common causes... FRCOphth exam preparation.
Bullous Pemphigoid
Key Facts Epidemiology : Most common autoimmune blistering disease; incidence 6-43 per million/year globally, increasing over past 3 decades Mean age of onset : 75-80 years; rare before 60 years Target antigens :...
Cellulitis and Erysipelas
Cellulitis is a common, spreading bacterial infection of the deep dermis and subcutaneous tissue, typically presenting with localised heat, redness (erythema), swelling (oedema), and pain. Erysipelas is a superficial...
Chickenpox (Varicella)
Chickenpox (varicella) is a highly contagious primary infection caused by varicella-zoster virus (VZV), a member of the ... MRCPCH, RCPCH Progress Test exam pre
Chronic Spontaneous Urticaria
Chronic Urticaria (CU) is defined as the recurrent occurrence of wheals (hives), angioedema, or both for more than 6 weeks . It affects 0.5-1% of the population and has a profound impact on quality of life comparable...
Contact Dermatitis
Comprehensive evidence-based guide to contact dermatitis: allergic and irritant mechanisms, diagnosis, patch testing, and management
Cryotherapy (Liquid Nitrogen Treatment)
Cryotherapy is one of the most commonly performed dermatological procedures worldwide, utilizing extreme cold—most frequently liquid nitrogen at -196°C—to selectively destroy abnormal or unwanted tissue through...
Dermatitis Herpetiformis
Dermatitis herpetiformis (DH) is a chronic, intensely pruritic vesiculobullous skin disease characterized by grouped ves... MRCP exam preparation.
Dermatofibroma
While dermatofibromas are entirely benign and require no treatment in the majority of cases, they serve as important clinical entities for several reasons: they are frequent causes of patient anxiety requiring...
Dermatomyositis
Dermatomyositis (DM) is an idiopathic inflammatory myopathy characterised by the combination of proximal muscle weakness... MRCP exam preparation.
Drug Eruptions: Stevens-Johnson Syndrome (SJS) & Toxic Epidermal Necrolysis (TEN)
Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) represent severe, life-threatening mucocutaneous dru... MRCP, Emergency Medicine exam prepar
Eczema Herpeticum
Key Facts Aetiology : HSV-1 (85-90% of cases) or HSV-2 infection on disrupted skin barrier Risk population : Predominantly atopic dermatitis patients (especially moderate-to-severe, childhood-onset disease) Incidence...
Emollients & Moisturisers
Emollients are medical moisturisers that form the cornerstone of therapy for all dry skin conditions including atopic de... MRCP(UK), MRCGP exam preparation.
Epidermoid & Pilar Cysts
Epidermoid and pilar (trichilemmal) cysts are the most common cutaneous cysts encountered in clinical practice, often incorrectly termed "sebaceous cysts." This terminology is a misnomer because these cysts contain...
Erysipelas
Primary Pathogen : Group A Streptococcus ( Strep pyogenes ) - 80-90% of cases Secondary Pathogens : Group G/C Streptococcus ( S. dysgalactiae ) - increasingly recognized Anatomical Depth : Upper dermis and superficial...
Erythema Multiforme
Historically, EM was incorrectly grouped with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) as part of a single disease spectrum. Current evidence firmly establishes EM as a distinct entity with...
Erythema Nodosum
The condition demonstrates female predominance (3-6:1) with peak incidence in the third and fourth decades. Löfgren's syndrome—the triad of erythema nodosum, bilateral hilar lymphadenopathy, and...
Glomus Tumor (Subungual)
A Glomus Tumor is a rare, benign, but exquisitely painful vascular neoplasm arising from the glomus body (Sucquet-Hoyer canal). The glomus body is a specialized arteriovenous anastomosis involved in thermoregulation,...
Glucagonoma
Dermatosis – Necrolytic Migratory Erythema (NME) Diabetes Mellitus – usually mild to moderate Deep Vein Thrombosis – hypercoagulable state Depression – neuropsychiatric manifestations
Hidradenitis Suppurativa
The disease manifests predominantly in areas with high concentrations of apocrine glands: axillae, groin, perineum, inframammary regions, and buttocks. It presents after puberty (typically second to third decade) and...
Hirsutism
Key Facts Definition : Excessive terminal hair growth in androgen-sensitive areas in women, quantified by modified Ferriman-Gallwey score ≥8. Prevalence : 5-15% of women of reproductive age; varies significantly by...
Human Papillomavirus (HPV) Infection
Human Papillomavirus (HPV) is a double-stranded DNA virus of the Papillomaviridae family, representing the most common sexually transmitted infection (STI) worldwide . Over 200 HPV genotypes have been identified, with...
Hyperhidrosis
The condition is classified into: Primary (Idiopathic) Focal Hyperhidrosis : Localized excessive sweating without identifiable cause, typically affecting axillae, palms, soles, or craniofacial regions Secondary...
IgA Vasculitis (Henoch-Schönlein Purpura)
IgA Vasculitis (IgAV), formerly known as Henoch-Schönlein Purpura (HSP), is the most common systemic vasculitis in childhood, with an annual incidence of 10-20 per 100,000 children. It is an immune-complex mediated...
IgA Vasculitis (Henoch-Schönlein Purpura)
IgA Vasculitis (IgAV), formerly known as Henoch-Schönlein Purpura (HSP) , is the most common systemic vasculitis in childhood , characterised by IgA1-dominant immune complex-mediated small vessel vasculitis affecting...
Impetigo (Child)
Impetigo is a highly contagious superficial bacterial skin infection that represents the most common bacterial skin infection in children worldwide , with peak incidence in 2-5 year olds . The condition is...
Infantile Seborrhoeic Dermatitis (Cradle Cap)
Infantile seborrhoeic dermatitis (ISD), commonly known as "cradle cap," is a benign, self-limiting inflammatory skin condition affecting infants primarily in the first 3 months of life. It presents characteristically...
Keloid & Hypertrophic Scars
Keloid and hypertrophic scars represent aberrant wound healing characterized by excessive fibroproliferative responses and abnormal collagen deposition . These pathological scars arise from dysregulation of the normal...
Keratoacanthoma
However, the benign classification of KA remains one of dermatology's most contentious issues. Histologically, KA is often indistinguishable from well-differentiated squamous cell carcinoma (SCC), and rare cases of...
Leishmaniasis
Comprehensive evidence-based guide to Leishmaniasis covering all three clinical forms (Cutaneous, Mucocutaneous, Visceral), epidemiology, pathophysiology, diagnosis, and management strategies with emphasis on liposomal...
Lichen Planus (Adult)
Lichen planus (LP) is a chronic, immune-mediated inflammatory disorder affecting the skin, mucous membranes, hair follicles, and nails. First described by Erasmus Wilson in 1869, it is characterized by a distinctive...
Lichen Sclerosus
The disease presents a diagnostic and therapeutic challenge requiring long-term management and surveillance. Despite being a benign condition, LS profoundly impacts patients through intractable pruritus, dyspareunia,...
Malignant Melanoma
Global Burden : Over 324,000 new cases diagnosed annually worldwide, with melanoma representing the 17th most common cancer globally. Incidence Variation : Highest in Australia/New Zealand (50-60 per 100,000),...
Melanoma
A comprehensive guide to Malignant Melanoma covering epidemiology, molecular pathophysiology (BRAF/NRAS/KIT mutations), AJCC 8th edition staging, sentinel lymph node biopsy, and modern immunotherapy/targeted therapy...
Molluscum Contagiosum (Child)
Molluscum contagiosum is a Common, Benign, Self-Limiting Viral Skin Infection caused by the Molluscum Contagiosum Virus (MCV) , a member of the Poxviridae family. It is characterised by Discrete, Dome-Shaped,...
Nappy Rash
The key clinical distinction is between Irritant Dermatitis (which characteristically affects convex surfaces and spares the flexures ) and Candidal Dermatitis (which involves the deep flexures and presents with...
Neurofibromatosis (NF1 & NF2)
Neurofibromatosis encompasses two distinct autosomal dominant neurocutaneous disorders: neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2). NF1, also known as von Recklinghausen disease, is the most...
Neurofibromatosis Type 1 (NF1)
NF1 is an autosomal dominant disorder caused by loss-of-function mutations in the NF1 tumour suppressor gene located on chromosome 17q11.2 . This gene encodes neurofibromin , a large cytoplasmic protein of 2,818 amino...
Pemphigus Vulgaris
Unlike Bullous Pemphigoid, the blisters are superficial (intra-epidermal) and rupture easily, often leaving large, painful, raw areas that are prone to infection. The disease typically begins with oral mucosal...
Penile Cancer
Human papillomavirus (HPV), particularly high-risk types 16 and 18, is detected in 30-50% of penile cancers through molecular studies, establishing a viral oncogenic pathway analogous to cervical cancer. Chronic...
Plantar Warts (Verrucae)
Plantar warts (verrucae plantares) are benign epithelial proliferations on the plantar surface of the feet caused by inf... MRCP, Primary Care exam preparation.
Polyarteritis Nodosa (PAN)
PAN can be idiopathic (most cases in developed countries) or associated with Hepatitis B Virus (HBV) infection (classic association, now less than 5% due to vaccination programs). The disease affects multiple organ...
Psoriasis
Plaque psoriasis (psoriasis vulgaris) accounts for 80-90% of cases and follows a relapsing-remitting course with significant impact on quality of life. Management follows a stepwise approach: topical therapy (vitamin...
Psoriatic Arthritis
CASPAR Criteria Gold Standard : Diagnosis requires established inflammatory arthritis (peripheral, spinal, or entheseal) PLUS ≥3 points from: current psoriasis (2), history of psoriasis (1), family history of...
Pyogenic Granuloma
The cardinal clinical feature is a dome-shaped, glistening, friable nodule that bleeds disproportionately to the degree of trauma, often with a characteristic collarette of scale at the base. While the lesion appears...
Rosacea (Adult)
Rosacea is a chronic inflammatory facial skin condition characterised by episodic or persistent central facial erythema, telangiectasia, inflammatory papules and pustules, and in advanced cases, phymatous tissue...
Scabies
Nocturnal Itch Pearl : The characteristic nocturnal pruritus occurs because mites are more active in warm environments. Night-time scratching + web space involvement = think scabies.
Seborrhoeic Keratosis
Seborrhoeic Keratosis (SK) is the most common benign tumour of the skin, originating from keratinocytes in the stratum b... MRCP, MRCGP exam preparation.
Skin Biopsy Techniques
Skin biopsy is a fundamental diagnostic procedure in dermatology, primary care, and plastic surgery, used to obtain tiss... MRCS exam preparation.
Skin Grafts
A skin graft is the transfer of epidermis and variable amounts of dermis from a donor site to a recipient wound bed, where it survives by developing a new blood supply from the underlying tissue. Unlike flaps (which...
Squamous Cell Carcinoma (Skin)
Cutaneous Squamous Cell Carcinoma (cSCC) is a malignant neoplasm arising from epidermal keratinocytes, representing the second most common skin cancer after basal cell carcinoma. Unlike basal cell carcinoma, cSCC...
Staphylococcal Scalded Skin Syndrome
Staphylococcal Scalded Skin Syndrome (SSSS) is an acute toxin-mediated exfoliative dermatosis caused by epidermolytic ex... MRCPCH, DCH exam preparation.
Sturge-Weber Syndrome (SWS)
Sturge-Weber Syndrome (SWS) is a rare, non-hereditary neurocutaneous disorder characterized by the clinical triad of:... MRCPCH, MRCP exam preparation.
Subungual Exostosis
The condition is clinically significant because it is frequently misdiagnosed as verruca vulgaris, onychomycosis, or ingrown toenail, leading to delayed treatment and prolonged symptoms. The diagnostic hallmark is a...
Sun Protection & Photoprotection
Sun protection encompasses the comprehensive strategies employed to prevent ultraviolet (UV) radiation-induced skin dama... MRCP exam preparation.
Syphilis (Treponema pallidum Infection)
Syphilis is a sexually transmitted infection (STI) caused by the spirochaete bacterium Treponema pallidum subspecies pallidum . Dubbed "The Great Imitator" for its remarkably diverse clinical manifestations, syphilis...
Systemic Lupus Erythematosus (SLE)
Systemic Lupus Erythematosus (SLE) is the distinct prototype of a systemic autoimmune disease. Unlike organ-specific des... MRCP exam preparation.
Systemic Mastocytosis
Clinical manifestations arise from two principal mechanisms: mast cell mediator release (causing flushing, urticaria, pruritus, anaphylaxis, gastrointestinal symptoms) and organ infiltration by neoplastic mast cells...
Tinea Infections
The three principal genera of dermatophytes are Trichophyton , Microsporum , and Epidermophyton . Trichophyton rubrum accounts for 60-80% of all dermatophyte infections globally and is the most common cause of chronic...
Tinea Infections (Dermatophytosis)
Dermatophytosis (tinea infections) represents a group of superficial mycoses caused by keratinophilic fungi of the genera Trichophyton , Microsporum , and Epidermophyton . These organisms infect keratinized...
Topical Corticosteroids
Potency: Matching strength to the site and severity (e.g., Mild for face, Super-potent for palms).
Tuberous Sclerosis Complex (TSC)
Tuberous Sclerosis Complex (TSC) is an autosomal dominant multisystem genetic disorder caused by mutations in either the... MRCP, FRACP exam preparation.
Urticaria (Hives)
CSU, representing approximately 70% of chronic cases, is frequently driven by autoimmune mechanisms involving autoantibodies against the high-affinity IgE receptor (FcεRI) or IgE itself. Angioedema , affecting deeper...
Venous Leg Ulcers
The pathognomonic presentation comprises a shallow, exudating ulcer typically located in the "gaiter area" (distal third of the leg, particularly the medial malleolar region), surrounded by characteristic stigmata of...
Viral Warts (Verrucae)
Viral warts are benign epithelial proliferations caused by infection of keratinocytes with Human Papillomavirus (HPV) . They represent one of the most common dermatological conditions, affecting up to 10-20% of...
Vitiligo
Vitiligo is an acquired, chronic pigmentary disorder characterized by the autoimmune destruction of melanocytes, resulti... MRCP exam preparation.
Vulval Cancer
HPV-dependent pathway (30-40%): Affects younger women (40-60 years), associated with High-Risk HPV infection (types 16, 18), characterized by usual-type Vulval Intraepithelial Neoplasia (uVIN), and demonstrates...