Makindo Medical Notes

Related Subjects: |Anatomy of Skin |Skin and soft tissue and bone infections | Skin or subcutaneous lump |Skin Pathology and Description and Examination

🧪 Pathology

📍 By Location

🔍 Examination – Types of Lesions

• 🔴 Macule: Flat lesion < 1 cm
• 🟠 Patch: Flat lesion > 1 cm
• 🔵 Papule: Elevated, palpable lesion < 1 cm
• 🟣 Plaque: Elevated, palpable lesion > 1 cm
• ⚪ Nodule: Deep, palpable lesion < 1 cm (dermal or subcutaneous)
• ⚫ Tumour: Deep, palpable lesion > 1 cm
• 💧 Vesicle: Fluid-filled lesion < 1 cm
• 💦 Bulla: Fluid-filled lesion > 1 cm
• 🟡 Cyst: Nodule with semi-solid or fluid material
• 🤢 Pustule: Elevated lesion with pus (white, grey, yellow, green)
• 🩹 Erosion: Epidermal disruption, heals without scarring
• 🩸 Ulcer: Extends into dermis, heals with scarring
• 🟤 Crust: Dried serum/blood/pus (e.g., impetigo)
• ⚖️ Scale: Excess keratin (e.g., seborrheic dermatitis)
• 🪵 Lichenification: Thickened skin with exaggerated markings (e.g., chronic eczema)
• ✂️ Fissure: Linear skin slit
• 🪶 Excoriation: Scratch mark
• 🌵 Xerosis: Pathological dryness of skin, mucosa, or conjunctiva
• ⬇️ Atrophy: Thinning/depression from reduced cell/tissue mass
• ⚫ Comedones: Sebum + keratin plugs in acne (blackheads/whiteheads)
• 🟣 Purpura: Non-blanchable dermal bleeding
• 🔴 Petechiae: Small pinpoint purpura
• 🟢 Ecchymosis: Larger flat purpura ("bruise")
• 🔍 Telangiectasia: Dilated superficial blood vessels, blanchable
• ⭐ Scar: Fibrosis replacing dermis/subcutis
• 💨 Wheal: Transient, blanchable dermal edema (e.g., urticaria)

📖 Descriptive Terms

• ✋ Acral: Hands & feet (e.g., hand-foot-mouth)
• ⭕ Annular: Ring-shaped (e.g., granuloma annulare)
• 🧵 Follicular: Hair follicle lesions (e.g., folliculitis)
• 💧 Guttate: Drop-like pattern (e.g., guttate psoriasis)
• ⚡ Koebner Phenomenon: Lesions appear at trauma sites (psoriasis, warts)
• 🌡️ Morbilliform: Measles-like maculopapular rash
• 🕸️ Reticular: Net-like (e.g., livedo reticularis)
• 🎯 Target/Iris: Concentric rings (e.g., erythema multiforme)
• 🌱 Satellite: Smaller lesions around a main one (e.g., candida)
• 🐍 Serpiginous: Snake-like (e.g., cutaneous larva migrans)
• ✨ Other: Discrete, clustered, linear, confluent, indurated

🦠 Infectious Causes

• 🟡 Impetigo: Honey-crust lesions (children). ➡️ Topical mupirocin; oral antibiotics if extensive.
• 🔴 Cellulitis: Red, hot, tender swelling (often leg). ➡️ Oral/IV antibiotics, limb elevation.
• ⭕ Tinea (Ringworm): Annular scaly plaques. ➡️ Topical antifungals (clotrimazole); oral terbinafine if severe.

🔥 Inflammatory Causes

• 🪨 Psoriasis: Silvery, well-demarcated plaques on extensors. ➡️ Topical steroids, phototherapy, methotrexate.
• 🌾 Eczema (Atopic Dermatitis): Itchy, erythematous, scaly patches (flexural). ➡️ Emollients, topical steroids, antihistamines.
• ☣️ Contact Dermatitis: Red, blistered rash after irritant/allergen. ➡️ Avoid trigger, topical steroids.

🦠 Viral Causes

• 🌋 Herpes Zoster (Shingles): Painful vesicular rash along dermatome. ➡️ Acyclovir, analgesia, gabapentin for pain.
• 🧩 Warts (Verrucae): Rough, raised lesions (hands/feet/genitals). ➡️ Salicylic acid, cryotherapy, excision.

🧬 Malignant Causes

• ⚪ Basal Cell Carcinoma (BCC): Pearly, vascular nodule (face). ➡️ Excision, Mohs, topical therapy if small.
• 🔺 Squamous Cell Carcinoma (SCC): Red nodule/ulcer on sun-exposed skin. ➡️ Excision, cryo, radiotherapy if advanced.
• ⚫ Melanoma: Asymmetric, irregular, colour-varied lesion (ABCDE). ➡️ Wide excision, lymph node biopsy, immunotherapy if advanced.

🔶 Other Causes

• 🌞 Actinic Keratosis: Scaly patches on sun-exposed skin; precancerous. ➡️ 5-FU cream, cryo, photodynamic therapy.
• 💜 Lichen Planus: Purple, polygonal, pruritic papules (wrists, ankles, genitals). ➡️ Steroids, antihistamines, phototherapy if severe.