Basic skin lesions

This PPt is about Skin lesions and their morphology , especially in pediatric age groups.

1. Basic skin lesions & their morphology Prepared by : Temesgen Girma C1 Medical student, SPHMMC, Addis Ababa, Ethiopia

2. When describing a skin lesion,it is important to note the following features :- Size Type shape and symmetry color and pigmentation surface area Distribution over the body surface

3. Types of lesion Primary skin lesions  are those which develop as a direct result of the disease process.  Secondary lesions  are those which evolve from  primary lesions  or develop as a consequence of the patient's activities . special skin lesion :- Specific for certain disease

4. SHAPES OF PAPULES AND NODULES Dome shaped Flat shaped Umblicated Acuminate

5. CONFIGURATION OF LESIONS Annular Round / discoid Polycyclic Arcuate Linear Reticular Serpiginous

6. ARRANGEMENT OF LESIONS Grouped/ herpetiform Scattered

7. DISTRIBUTION OF LESIONS Sun exposed Sun protected Acral Truncal Extensor Flexor Localized Generalized B/L symmetrical Universal

8. Primary skin lesions Macule Patch Papule Plaque Nodule Vesicle Bulla Pustule Abscess Wheal Cyst

9. Macules A flat circumscribed lesion showing change in color without change in its consistency. Macules are nonpalpable . They are 0.5cm-1cm in size.

10. patch A large macule is called patch (>1cm in size ). May have scaling . Eg :- Vitiligo, melasma , pityriasis alba

11. Papules A small, solid lesion, <0.5 cm in diameter, raised above the surface of surrounding skin & hence palpable. Papules may be of various colors.

12. Plaque It is an indurated area of skin larger than 0.5 cm in diameter which may be raised or depressed from skin surface.

13. Nodule A large ( 0.5 – 5.0 cm ), firm lesion raised above the surface of surrounding skin. It is the depth of involvement that differentiates a nodule from a large papule. Surface- smooth, keratotic,ulcerated or fungating .

14. Vesicle A small, fluid filled lesion, <0.5 cm in diameter, raised above the plane of surrounding skin. Fluid is often visible and the lesions are translucent

15. Bulla A fluid filled, raised, often a translucent lesion >0.5cm in diameter E.g. Bullous pemphigoid

16. Pustule A vesicle filled with pus It is formed due to collection of inflammatory exudate rich in leucocytes. It may contain bacteria or may be sterile.

17. Abscess A localized collection of pus deep in dermis or subcutaneous tissue Due to deep seated location pus may not be visible on skin surface but would show sign of inflammation.

18. Wheal It is a transient swelling of skin disappearing within 24 hrs. It is formed due to sudden extravasation of fluid in the dermis. E.g : urticaria

19. Cyst It is a spherical or oval sac or an encapsulated cavity containing fluid or semi solid material. It is lined with true epithelium. E.g :- mucous retention cyst

20. Secondary Skin Lesions Scale Crust Erosion Fissure Scar

21. Scale Excess dead epidermal cells that are produced by abnormal keratinization and shedding Eg : Psoriasis, Icthyosis

22. Staphylococcal scalded skin syndrome

23. Crust Dried exudate of body fluids (blood / serous fluid) Which might be either yellow / red

24. Erosion A focal loss of epidermis Erosions do not penetrate below the dermoepidermal junction and therefore heal without scarring Eg :- tinea pedis

25. ulcer A focal loss of epidermis and/or dermis Scarring depends on the depth of the ulcer

26. Fissure It is a linear loss of continuity of skin due to excessive tension . Eg :- eczema(fingertips)

27. Scar It is replacement of normal skin by fibrous tissue in the process of healing of damaged skin. Scars are of two typeshypertrophic and atrophic.

28. Special Lesions Burrow Purpura Ulcer Malar rash

29. Burrow It is a serpentine tunnel made by scabies mite in stratum corneum . The open end of the tunnel has a papule.

30. Purpura Extravasation of red blood cells from cutaneous vessles in skin & mucous membrane. Diascopy- non blanchable .

31. Malar Rash of lupus is red or purplish and mildly scaly. the rash spares the  nasolabial folds  of the face It is usually macular with sharp edges, and not itchy

32. Thank You!