Skin Conditions Glossary: Complete Dermatological Health Guide

The skin, the body’s largest organ, serves as the interface between the internal organism and the external environment. Weighing approximately 8 pounds and covering roughly 20 square feet in adults, the skin performs critical functions including protection against pathogens, regulation of temperature and fluid balance, sensation, and synthesis of Vitamin D. Skin conditions, disorders affecting this vital organ, are extraordinarily common, affecting virtually everyone at some point in their lives. In Dubai’s desert climate with intense sun exposure, air conditioning, and diverse population, dermatological conditions present unique challenges and considerations.

The skin consists of three main layers. The epidermis, the outermost layer, is a stratified squamous epithelium that provides the primary barrier function. Keratinocytes are the predominant cell type, differentiating from basal layer to form the protective stratum corneum. Melanocytes produce melanin, determining skin color and providing UV protection. Langerhans cells participate in immune surveillance. Merkel cells function in sensation.

The dermis, the middle layer, provides structural support and elasticity. It contains fibroblasts that produce collagen and elastin, the extracellular matrix proteins responsible for skin strength and flexibility. Blood vessels regulate temperature and nourish the epidermis. Nerves provide sensation. Hair follicles, sebaceous glands, and sweat glands are skin appendages embedded in the dermis.

The subcutaneous tissue (hypodermis), the deepest layer, consists of adipose tissue providing insulation, cushioning, and energy storage. It also contains larger blood vessels and nerves.

Eczema

Definition and Overview

Eczema, also known as atopic dermatitis, is a chronic inflammatory skin condition characterized by itchy, inflamed skin that typically follows a relapsing course. It is the most common chronic skin disease in children and frequently persists into adulthood. Eczema affects approximately 15-20 percent of children and 1-3 percent of adults in developed countries, with prevalence increasing globally.

The pathophysiology involves skin barrier dysfunction (filaggrin mutations impair barrier function), immune dysregulation (Th2 inflammation), and environmental triggers. The “atopic march” describes the progression from eczema to allergic rhinitis and asthma in many affected individuals. Genetic factors, environmental exposures, and immune responses all contribute to disease development and persistence.

Symptoms and Presentation

The hallmark of eczema is pruritus (itch), which may be severe and disabling. Scratching perpetuates the itch-scratch cycle, causing skin damage and inflammation. In acute flares, skin appears red, swollen, vesicular (blistered), and weeping. In chronic eczema, skin becomes thickened (lichenified), hyperpigmented or hypopigmented, and leathery from chronic scratching.

Distribution varies by age. In infants, eczema typically affects the face, scalp, and extensor surfaces. In children and adults, flexural creases (antecubital and popliteal fossae), neck, wrists, and ankles are commonly involved. Hand eczema and nummular (coin-shaped) eczema are variants.

Associated features include xerosis (dry skin), ichthyosis vulgaris (inherited scale), keratosis pilaris (rough bumps on arms), Dennie-Morgan lines (extra creases under eyes), and allergic shiners (dark circles). Patients often have personal or family history of atopic disease (asthma, allergic rhinitis).

Triggers and Aggravating Factors

Many factors can trigger or worsen eczema flares. Environmental triggers include extreme temperatures (hot weather, sweating, cold dry winter air), low humidity (air conditioning, desert climate), and airborne allergens (dust mites, pollen, pet dander). Irritants include soaps, detergents, fragrances, solvents, and wool or synthetic fabrics.

Infections can trigger flares. Staphylococcus aureus colonization is common and can worsen inflammation. Viral infections (eczema herpeticum) can cause severe complications in patients with eczema. Fungal infections may also trigger flares.

Psychological stress is a well-recognized trigger. Hormonal changes, particularly in women, can affect eczema severity. Sweating and exercise may trigger itching in some patients.

Treatment and Management

The foundation of eczema management is moisturization. Frequent application of fragrance-free emollients restores skin barrier function and reduces transepidermal water loss. Thick ointments (petrolatum, mineral oil) are more effective than lotions. Application within 3 minutes of bathing (“soak and seal”) maximizes benefit.

Topical corticosteroids remain first-line for active inflammation. Potency is chosen based on location and severity: low-potency (hydrocortisone 1%) for face and intertriginous areas, medium to high-potency (triamcinolone, betamethasone) for trunk and limbs. Prolonged use on thin skin can cause atrophy, striae, and telangiectasia.

Topical calcineurin inhibitors (tacrolimus ointment, pimecrolimus cream) are steroid-sparing alternatives for sensitive areas (face, neck, flexures). They do not cause skin atrophy but may cause transient burning.

Systemic treatments for moderate to severe eczema include oral corticosteroids (short courses only), methotrexate, azathioprine, cyclosporine, and newer biologic agents. Dupilumab (anti-IL-4R) is approved for moderate to severe atopic dermatitis and has revolutionized treatment.

Wet wrap therapy, phototherapy (narrowband UVB), and avoidance of identified triggers are additional management strategies. Education about the chronic nature of eczema and proper skincare is essential.

Psoriasis

Definition and Overview

Psoriasis is a chronic immune-mediated inflammatory disease characterized by well-demarcated, erythematous plaques with silvery scale. It affects approximately 2-3 percent of the global population, occurring equally in men and women. Onset is typically in the second to third decade, though it can occur at any age.

The pathophysiology involves T-cell mediated inflammation with Th1 and Th17 responses, leading to keratinocyte hyperproliferation and dermal inflammation. Genetic factors (PSORS1 and other loci) and environmental triggers (infections, stress, trauma, medications) contribute to disease expression.

Several clinical variants exist. Plaque psoriasis (psoriasis vulgaris) is the most common, presenting with well-demarcated plaques on extensor surfaces (elbows, knees), scalp, and lower back. Guttate psoriasis presents with small, teardrop-shaped lesions, often triggered by streptococcal infection. Inverse psoriasis affects intertriginous areas (armpits, groin). Pustular psoriasis features sterile pustules. Erythrodermic psoriasis causes generalized redness and scaling.

Symptoms and Associated Conditions

The primary symptom of psoriasis is the visible skin lesions, which may be asymptomatic or itchy. Scalp psoriasis can cause thick scaling that may be confused with dandruff. Nail psoriasis produces pitting, onycholysis (separation from nail bed), and oil-drop discoloration. Inverse psoriasis presents as smooth, shiny lesions in body folds.

Psoriatic arthritis develops in approximately 30 percent of patients, causing joint pain, swelling, and potential joint destruction. It can affect any joint and may cause dactylitis (“sausage digits”) and enthesitis (inflammation at tendon insertions).

Metabolic syndrome, cardiovascular disease, depression, and inflammatory bowel disease are more common in psoriasis patients. This association may result from chronic inflammation and shared risk factors.

Treatment and Management

Topical treatments are first-line for mild to moderate disease. Corticosteroids of various potencies are used based on location. Vitamin D analogs (calcipotriene, calcitriol) reduce cell proliferation and are often combined with steroids. Coal tar, anthralin, and keratolytics (salicylic acid) have older but established roles.

Phototherapy (narrowband UVB) is effective for moderate disease, typically requiring 2-3 treatments per week for several weeks. PUVA (psoralen plus UVA) is more effective but has higher long-term skin cancer risk.

Systemic treatments include traditional agents (methotrexate, cyclosporine, acitretin) and newer biologic agents. Biologics targeting TNF-alpha (etanercept, adalimumab, infliximab, certolizumab), IL-12/23 (ustekinumab), IL-17 (secukinumab, ixekizumab, brodalumab), and IL-23 (guselkumab, tildrakizumab, risankizumab) have transformed psoriasis treatment, achieving clear or almost clear skin in most patients.

Lifestyle management includes weight loss, moderation of alcohol, smoking cessation, and stress management. Joint symptoms require rheumatology input for psoriatic arthritis management.

Acne

Definition and Overview

Acne vulgaris is one of the most common skin conditions, affecting approximately 85 percent of adolescents and young adults to some degree. While often considered a teenage condition, adult acne is increasingly common, particularly in women. Acne can cause significant psychological distress and scarring.

The pathophysiology involves four key factors: increased sebum production (androgen-stimulated sebaceous gland activity), follicular hyperkeratinization (abnormal shedding of skin cells clogging pores), Cutibacterium acnes (formerly Propionibacterium acnes) colonization, and inflammation. Hormonal factors play a major role, explaining the distribution (face, chest, upper back) and flares related to menstrual cycle, pregnancy, and PCOS.

Classification and Presentation

Acne is classified by severity and morphology. Mild acne features predominantly comedones (blackheads and whiteheads) with few inflammatory lesions. Moderate acne has more inflammatory papules and pustules. Severe nodulocystic acne features deep, painful nodules and cysts that can cause scarring.

Common locations include the face (forehead, cheeks, chin), chest, and upper back. Post-inflammatory hyperpigmentation (dark marks) and erythema (red spots) are common sequelae, particularly in darker skin types. True scarring occurs in more severe inflammatory acne.

Acne variants include acne conglobata (severe inflammatory with interconnecting abscesses), acne fulminans (acute febrile illness with ulcerating nodules), and acne mechanica (from friction and occlusion, common in athletes).

Treatment and Management

Treatment follows a step-wise approach based on severity. For mild acne, topical agents are first-line. Benzoyl peroxide kills C. acnes and has mild comedolytic effects. Topical retinoids (tretinoin, adapalene, tazarotene) normalize follicular keratinization. Topical antibiotics (clindamycin, erythromycin) reduce bacterial load and inflammation. Combination products improve adherence.

For moderate acne, oral antibiotics (doxycycline, minocycline, tetracycline) are added to topical therapy. Hormonal therapy (combined oral contraceptives, spironolactone) is particularly effective in women. Isotretinoin (oral retinoid) is reserved for severe, recalcitrant acne due to potential side effects including teratogenicity, mucocutaneous dryness, and lipid elevation.

Procedural treatments include extraction of comedones, chemical peels, light therapy (blue light, photodynamic therapy), and intralesional steroid injections for cystic lesions. Scarring can be improved with laser resurfacing, microneedling, chemical reconstruction, or surgical excision.

Lifestyle recommendations include gentle cleansing (avoid scrubbing), non-comedogenic moisturizers and cosmetics, avoiding picking or squeezing lesions, and managing stress. Diet’s role is debated, but some patients benefit from reducing high-glycemic foods and dairy.

Rosacea

Definition and Overview

Rosacea is a chronic inflammatory facial skin condition characterized by persistent facial redness, visible blood vessels (telangiectasia), papules, pustules, and in some cases, rhinophyma (thickened, bumpy nose). It typically affects fair-skinned adults aged 30-60, more commonly women, though men may have more severe manifestations.

The pathophysiology involves dysregulation of the innate immune system (cathelicidin antimicrobial peptide abnormalities), neurovascular changes, and alterations in the skin microbiome. Demodex mites may play a role in some patients. Triggers include hot beverages, alcohol, spicy foods, temperature extremes, sunlight, stress, and certain cosmetics.

Subtypes and Symptoms

Four subtypes are recognized, though many patients have features of more than one. Erythematotelangiectatic rosacea features persistent central facial flushing, erythema, and telangiectasia. Papulopustular rosacea features papules and pustules in a central facial distribution, resembling acne. Phymatous rosacea causes skin thickening and nodularity, most commonly affecting the nose (rhinophyma). Ocular rosacea affects the eyes, causing dryness, irritation, and blepharitis.

Symptoms include burning, stinging, and sensitivity. Rhinophyma, when present, can cause nasal obstruction. Ocular involvement may precede skin findings and can cause serious eye complications.

Treatment and Management

Trigger avoidance is fundamental. Patients should identify and avoid personal triggers. Sun protection (broad-spectrum sunscreen, hats, shade) is essential.

Topical treatments for mild to moderate disease include metronidazole, azelaic acid, ivermectin, brimonidine (for erythema), and oxymetazoline (for erythema). Topical ivermectin has both anti-inflammatory and anti-parasitic properties.

Oral antibiotics (doxycycline, minocycline) are used for moderate to severe papulopustular rosacea. Low-dose doxycycline (40 mg extended-release) is FDA-approved for rosacea with fewer side effects than higher doses used for infections.

For severe or refractory disease, oral isotretinoin may be used. Procedural treatments for telangiectasia and persistent erythema include laser therapy (pulsed dye laser, KTP laser, IPL) and electrocautery.

Ocular rosacea requires ophthalmology consultation. Treatment includes artificial tears, warm compresses, and oral antibiotics. Topical cyclosporine may be used.

Vitiligo

Definition and Overview

Vitiligo is an acquired depigmentation disorder characterized by loss of functional melanocytes from the epidermis, resulting in white patches on skin and sometimes hair. It affects approximately 0.5-2 percent of the global population, occurring equally in men and women, with onset typically before age 20.

The pathophysiology involves autoimmune destruction of melanocytes. Evidence includes association with other autoimmune diseases, presence of autoantibodies, and response to immunosuppressive treatments. Genetic susceptibility involves multiple loci (NLRP1, PTPN22, AIRE) conferring risk.

Classification and Presentation

Vitiligo is classified as segmental (unilateral, often self-limited after 1-2 years) or non-segmental (bilateral, progressive, most common). Non-segmental vitiligo includes generalized, universalis (extensive), and acrofacial patterns. Mixed vitiligo has features of both patterns.

Presentation is asymptomatic depigmented patches, typically on sun-exposed areas, body folds, around body orifices, and prior injury sites (Koebner phenomenon). Hair in affected areas may turn white (poliosis). Depigmentation is permanent without treatment.

Associated autoimmune conditions include thyroid disease (most common), type 1 diabetes, alopecia areata, pernicious anemia, and Addison’s disease.

Treatment and Management

Treatment aims to halt progression, induce repigmentation, and achieve repigmentation maintenance. Early treatment offers best prognosis. Combination therapy is typically more effective than monotherapy.

Topical corticosteroids are first-line for limited disease, used for 2-4 months with breaks to prevent atrophy. Topical calcineurin inhibitors (tacrolimus, pimecrolimus) are steroid-sparing alternatives for sensitive areas. Topical JAK inhibitors (ruxolitinib) are newer options.

Phototherapy (narrowband UVB) is first-line for extensive disease, requiring 2-3 treatments per week for 6-12 months or longer. Excimer laser targets specific patches. PUVA is less commonly used now.

Surgical treatments (minigrafting, suction blister grafting, melanocyte transplantation) are options for stable vitiligo refractory to medical treatment. Psychological support is important given the significant impact on quality of life.

Skin Cancer

Definition and Overview

Skin cancer is the most common cancer globally, with incidence rising due to increased UV exposure and aging populations. The three main types are basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. Basal cell carcinoma is by far the most common, followed by squamous cell carcinoma. Melanoma is less common but more aggressive.

UV radiation (UVB causes direct DNA damage, UVA generates reactive oxygen species) is the primary environmental risk factor. Fair skin, history of sunburns (especially childhood), tanning bed use, immunosuppression, and certain genetic syndromes (xeroderma pigmentosum, basal cell nevus syndrome) increase risk.

Basal Cell Carcinoma

Basal cell carcinoma arises from basal cells in the epidermis. It is locally invasive but rarely metastasizes. Presentation includes pearly papules with telangiectasia (classic nodular BCC), superficial scaly patches (superficial BCC), or indurated plaques (morpheaform BCC). Common locations include head and neck.

Treatment options include surgical excision (gold standard), curettage and electrodessication (for low-risk lesions), Mohs micrographic surgery (for high-risk locations), topical treatments (imiquimod, 5-FU for superficial BCC), and radiation. Vismodegib and sonidegib (Hedgehog pathway inhibitors) are used for advanced BCC.

Squamous Cell Carcinoma

Squamous cell carcinoma arises from keratinocytes. It has metastatic potential (1-5 percent for most lesions, higher for high-risk lesions). Presentation includes indurated papules, plaques, or nodules with hyperkeratotic surface (“cutaneous horn”). Common locations include sun-exposed areas, lips, and scars.

High-risk features include size greater than 2 cm, depth greater than 2 mm, poor differentiation, perineural invasion, location on ear or non-hair-bearing lip, and immunosuppression.

Treatment involves surgical excision (with appropriate margins) or Mohs surgery. Radiation is alternative for non-surgical candidates. Advanced SCC may require cemiplimab (PD-1 inhibitor) or other systemic therapies.

Melanoma

Melanoma arises from melanocytes. It is the least common but most aggressive skin cancer, with significant metastatic potential. The ABCDE criteria help identify suspicious lesions: Asymmetry, Border irregularity, Color variation, Diameter greater than 6 mm, Evolution. Melanoma can arise in existing nevi or de novo.

Biopsy (excisional or incisional) is diagnostic. Staging ( Breslow thickness, ulceration, mitoses, lymph node involvement, metastasis) guides prognosis and treatment. Sentinel lymph node biopsy is used for staging intermediate-thickness melanoma.

Treatment for early melanoma is wide local excision. For advanced disease, immunotherapy (anti-PD-1 agents pembrolizumab, nivolumab; CTLA-4 inhibitor ipilimumab) and targeted therapy (BRAF/MEK inhibitors for BRAF-mutant melanoma) have dramatically improved survival.

Fungal Infections

Overview

Fungal infections of the skin are caused by dermatophytes (tinea infections), yeasts (Candida, Malassezia), or molds. They are common and range from mild to severe. Risk factors include warm and humid environments, immunosuppression, diabetes, and occlusive footwear.

Tinea corporis (ringworm) presents as annular plaques with advancing scaly border and central clearing. Tinea pedis (athlete’s foot) affects feet, with maceration between toes or dry scaling on soles. Tinea cruris (jock itch) affects groin folds. Tinea capitis affects scalp, causing patchy hair loss with scaling. Tinea unguium (onychomycosis) causes nail thickening, discoloration, and crumbling.

Treatment involves topical or oral antifungal agents depending on extent and location. Topical agents (clotrimazole, terbinafine, ketoconazole) are used for limited disease. Oral terbinafine or itraconazole is used for extensive disease, tinea capitis, or onychomycosis.

Frequently Asked Questions

Eczema Questions

Is eczema contagious? No, eczema is not contagious. It results from genetic and immune factors, not an infection.

Can eczema be cured? Eczema cannot be cured but can be effectively managed. Many children outgrow eczema by adolescence. Even persistent eczema can be controlled with proper treatment and skincare.

What is the best moisturizer for eczema? Fragrance-free ointments and creams work best. Look for petrolatum, mineral oil, ceramide-containing products, or glycerin-based formulations. Avoid products with fragrances, dyes, or known irritants.

Do food allergies cause eczema? Food allergies can trigger eczema flares in some patients, particularly infants with severe eczema. However, food allergy is not the primary cause of eczema. Testing should be reserved for patients with documented food triggers.

Psoriasis Questions

Is psoriasis just a skin disease? No, psoriasis is a systemic inflammatory disease with skin, joint (psoriatic arthritis), and metabolic manifestations. The inflammation affects the entire body.

Can psoriasis be spread to others? No, psoriasis is not contagious. It is an autoimmune condition with genetic and environmental triggers.

Does diet affect psoriasis? Diet may influence psoriasis in some individuals. Weight loss improves psoriasis in overweight patients. Alcohol and processed foods may worsen symptoms. Some patients report benefit from anti-inflammatory diets.

Is psoriasis curable? Psoriasis can be cleared with treatment, but it is a chronic condition with potential for recurrence. Long-term maintenance treatment is typically needed.

Acne Questions

Does chocolate cause acne? No direct evidence links chocolate to acne. However, high-glycemic diets may worsen acne in some individuals. Chocolate itself is not a direct cause.

Does popping pimples help? No, popping pimples can cause scarring, hyperpigmentation, and spread inflammation. Lesions should be allowed to heal naturally or treated professionally.

Is acne only a teenage problem? No, adult acne is common, particularly in women. Hormonal factors, stress, and skincare products contribute to adult-onset acne.

What causes cystic acne? Cystic acne results from deep inflammation and rupture of follicles. It has strong hormonal components and tends to run in families. Isotretinoin is often required for treatment.

Rosacea Questions

What triggers rosacea? Common triggers include hot beverages, alcohol (especially red wine), spicy foods, temperature extremes, sunlight, wind, stress, and certain cosmetics. Triggers are individual.

Is rosacea caused by poor hygiene? No, rosacea is not caused by poor hygiene. Over-cleansing can actually worsen symptoms. Gentle cleansing is recommended.

Can rosacea be cured? Rosacea can be effectively managed but not cured. Symptoms tend to wax and wane. Long-term maintenance treatment is usually needed.

Skin Cancer Questions

How do I check for skin cancer? Perform regular self-examinations, looking for new or changing lesions. The ABCDE criteria help identify suspicious lesions. Any concerning lesions should be evaluated by a dermatologist.

Is skin cancer only from sun exposure? Most skin cancers are UV-related, but some occur without sun exposure (acral melanoma, some BCCs). Complete skin examination is important.

Do I need skin checks if I have dark skin? Yes, people of all skin tones can develop skin cancer. Melanoma often occurs in acral locations (palms, soles, nails) in darker-skinned individuals.

Can skin cancer be treated? Most skin cancers are highly curable when detected and treated early. Melanoma is more serious but treatable when caught before metastasis.

General Questions

How often should I see a dermatologist? Annual skin examinations are recommended for everyone. Higher-risk individuals (history of skin cancer, immunosuppression, numerous moles) may need more frequent checks.

What causes dry skin? Dry skin results from impaired barrier function, often from genetics, environment (low humidity, cold weather), aging, harsh soaps, or underlying conditions like eczema.

Why does my skin itch? Itch has many causes including dry skin, eczema, psoriasis, allergies, medications, liver disease, kidney disease, and psychological factors. Evaluation is needed for persistent itch.

Key Takeaways

Skin conditions encompass a vast range of disorders from common acne and eczema to serious conditions like skin cancer. The skin’s visible nature means these conditions significantly impact quality of life and psychological wellbeing.

Eczema, a chronic inflammatory condition, requires consistent moisturization, anti-inflammatory treatment, and trigger avoidance. Modern biologic therapies have transformed treatment for moderate to severe disease.

Psoriasis, another inflammatory skin condition, shares pathways with metabolic and cardiovascular disease. Treatment has advanced dramatically with biologic agents targeting specific inflammatory pathways.

Acne, the most common skin condition, ranges from mild to severe. Treatment follows a step-wise approach from topicals to oral medications, with scarring prevention as a key goal.

Rosacea requires trigger identification and avoidance, along with medical and procedural treatment for persistent symptoms.

Vitiligo, while not physically harmful, has significant psychological impact. Treatment options continue to expand, though repigmentation remains challenging.

Skin cancer prevention through sun protection and early detection through regular skin checks saves lives. Dubai’s intense sun exposure makes sun protection particularly important.

For Dubai residents, the climate, sun exposure, and air conditioning create specific skin challenges. Access to dermatology care supports management of these conditions.

Natural support strategies including gentle skincare, stress management, and appropriate nutrition complement conventional treatment. Traditional approaches including Ayurveda provide additional perspectives on skin health.

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Related Services

At Healer’s Clinic Dubai, we offer comprehensive dermatological health support through our integrated services:

• Consultation and Diagnosis: Our experienced dermatologists provide thorough skin assessments, including dermoscopy and biopsy when needed, with personalized treatment plans.

• Homeopathic Condition Support: Our homeopathic practitioners offer individualized remedies to support skin wellness alongside conventional treatment.

• Ayurvedic Skin Care: Traditional Ayurvedic approaches including specialized diet plans (blood-purifying foods), herbal formulations, and lifestyle guidance support skin health from an ancient perspective.

• Skin Health Support: Our team provides comprehensive approaches for chronic skin conditions, including skincare education and complementary therapies.

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Medical Disclaimer: This glossary is provided for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read in this material. If you think you may have a medical emergency, call your doctor or emergency services immediately.