Dermatoses Resulting from Physical Factors

1. Dermatoses Resulting from Physical Factors Chapter 3 Andrew’s Diseases of the Skin Ben Adams, D.O. July 25th 2006

2. Heat Injuries • Thermal Burns • Electrical Burns • Miliaria • Miliaria Crystalline (Sudamina) • Miliaria Rubra (Prickly Heat, Heat Rash) • Miliaria Pustulosa • Miliaria Profunda • Occlusion Miliaria

3. Thermal Burns • First-degree burn: active congestion of superficial blood vessels • This causes erythema, sometimes followed by epidermal desquamation • Constitutional reactions occur if large area involved • Pain and increased surface heat may be severe

4. Deep Pale and anesthetic Injury to reticular dermis compromises blood flow and destroys appendages Healing takes > 1 month Scarring occurs Superficial Transudation of serum causing edema of superficial tissues Vesicles and blebs Complete recovery without scar or blemish is usual Second-degree burns

5. Second-degree burn • Thermal burn: This superficial second degree burn is characterized by bullae that contain serous fluid

6. Second-Degree Burns • Inflicted scalds: severe second degree burns after dipping • B: two days after incident-to lower extremities and perineum • C: foot and lower leg

7. Second-Degree Burn • Accidental scald • Splash-and-droplet pattern of an accidental scald from hot cup of tea

8. Full-thickness tissue loss Skin appendages are destroyed There is no epithelium for regeneration Healing leaves a scar Third-degree burns

9. Fourth-degree burns • Destruction of entire skin and subcutaneous fat with any underlying tendons

10. Rule of nines: • In adults, an estimate of burn extent based upon this surface area distribution chart. • Infants & children have a relatively increased head; trunk surface area ratio

11. Electrical Burns • Contact- small but deep, causing some necrosis of underlying tissues • Flash-burns usually cover a large area and are similar to a surface burn and should be tx as such • Lightning is the most lethal type of strike, cardiac arrest or other internal injuries may occur

12. Electrical Burns • Indirect- burns that are either linear in areas at which sweat was present; are feathery or aborescent pattern, which is believed to be pathognomonic

13. Electrical Burn • It is characterized by erythema, edema, bulla formation and sloughing of the necrotic epidermis

14. Electrical Burn-pathology • Blistering and elongated keratinocytes

15. Miliaria • Retention of sweat as a result of occlusion • Common in hot, humid climates • Occlusion of eccrine sweat gland obstructs delivery of sweat to the skin surface • Eventually backed-up pressure causes rupture of sweat gland or duct at different levels • Escape of sweat into adjacent tissue produces miliaria • Different forms of miliaria occur depending on the level of injury to the sweat gland

16. Miliaria Crystallina • Small, clear, superficial vesicles without inflammation • Appears in bedridden pts and bundled children • Lesions are asymptomatic and rupture at the slightest trauma • Self-limited; no tx is required

17. Miliaria Crystallina • Minute, discrete vesicles resulting from profuse sweating secondary to a high fever

18. Miliaria Rubra • Discrete, extremely pruritic, erythematous papulovesicles with sensation of prickling, burning, or tingling • Site of injury is prickle cell layer where spongiosis is produced

19. Miliaria Rubra

20. Miliaria Pustulosa • Always preceded by some injury, destruction, or blocking of sweat duct • Pustules independent of hair follicle • Seen in intertriginous areas, flexure surfaces of extremities, scrotum, and back of bedridden pts • Sterile pustules

21. Miliaria Profunda • Nonpruritic, flesh-colored, deep-seated, whitish papules • Asymptomatic, usually lasting only 1 hr after overheating has ended • Concentrated on the trunk and extremities • Occlusion is in upper dermis • Only seen in tropics usually following a severe bout of miliaria rubra

22. Occlusion Miliaria • May be produced with accompanying anhidrosis and increased heat stress susceptibility after application of extensive polyethylene film occlusion for > 48 hrs • Tx-place pt in a cool environment • Even a night in an air-conditioned room helps alleviate the discomfort

23. Occlusion Miliaria • Mild cases may respond to dusting powders, such as cornstarch or talcum powder • A lotion containing 1% menthol and glycerin and 4% salicylic acid in 95% alcohol is effective • An oily “shake” lotion such as calamine lotion, with 1% or 2% phenol may be effective

24. Erythema (pigmentatio) Ab Igne • Aka “toasted skin” syndrome • Persistent erythema or coarsely reticulated residual pigmentation resulting from it • Produced by long-continued exposure to excessive heat without production of a burn • It begins as a mottling caused by local hemostasis and becomes a reticulated erythema, leaving pigmentation

25. Erythema Ab Igne • Reticulated hyperpigmentation with some epidermal atrophy and scaling secondary to use of a heating pad

26. Use of bland emollients is helpful No effective treatment Kligman’s combination of 5% hydroquinone in hydrophilic ointment containing 0.1% retinoic acid and 0.1% dexamethasone may reduce unsightly pigmentation Erythema Ab Igne

27. There is a mild superficial perivascular inflammatory infiltrate composed predominantly of lymphocytes and prominent pigment incontinence. • Histologically, an increased amount of elastic tissue in the dermis is seen • Changes are similar to actinic elastosis, and has been suggested to call these changes thermal elastosis

28. Cold Injuries • Chilblains • Frostbite • Immersion injury

29. Chilblains • Acute chilblains is the mildest form of cold injury • Pts are usually unaware of injury until they develop burning, itching, and redness

30. Treatment • Nifedipine 20mg TID • Vasodilators (nicotinamide 100 mg TID or dipyridamole 25 mg TID) • Systemic corticoid tx is helpful in chilblain lupus erythematosus • Pentoxifylline may be useful • Smoking strongly discouraged

31. Frostbite • When soft tissue is frozen and locally deprived of blood supply • Frozen part is painless and becomes pale and waxy • Four stages: • I- Frost-nip erythema, edema,cutaneous anesthesia & transient pain • II- second degree: hyperemia, edema & blistering, with clear fluid in bullae • III- third-degree: full-thickness dermal loss with hemorrhagic bullae formation or waxy, dry, mummified skin • IV- full-thickness loss of entire part

32. First-Degree Frostbite

33. Immersion Foot Syndromes • Trench Foot • Warm Water Immersion Foot

34. Trench Foot • Term derived from trench warfare in World War I, when soldiers stood, sometimes for hours, in trenches with a few inches of cold water in them • Results from prolonged exposure to cold, wet conditions without immersion or actual freezing • Tx-removal from environment

35. Tropical Immersion Foot • AKA “paddy foot” in Vietnam • Seen after continuous immersion of the feet in water or mud of temperatures above 71.6 degrees F (22 degrees C) for 2-10 days • Erythema, edema, and pain of the dorsal feet • Also fever and adenopathy • Resolution occurs 3 to 7 days after the feet have been dried

36. Dermatoses with Cold Hypersensitivity • Erythrocyanosis Crurum • Acrocyanosis • Cold Panniculitis

37. Slight swelling and a bluish pink tint of the skin of the legs and thighs of young girls and women May be unilateral May have cramps in the legs at night Small tender nodules may be found on palpation Nodules may break down and form small, multiple ulcers Seen in northern countries and probably due to an abnormal reaction of blood vessels to prolonged cold Erythrocyanosis Crurum

38. Acrocyanosis • A persistent cyanosis with coldness and hyperhidrosis of hands and feet • Chiefly occurs in young women • At times, on cold exposure, a digit becomes stark white and insensitive (acroasphyxia) • Cyanosis increases as the temperature decreases and changes to erythema with elevation of dependent part • Cause is unknown • Smoking, coffee, and tea should be avoided

39. Acrocyanosis

40. Cold Panniculitis • After exposure to severe cold, well-demarcated erythematous warm plaques may develop, particularly on the cheeks of young children • Lesions usually develop within a few days after exposure, and resolve spontaneously in 2 weeks (approx) • No tx is indicated • Popsicle dermatitis is a temporary redness and induration of the cheek in children resulting from sucking Popsicles

41. Parts of solar spectrum important to photomedicine: Visible light 400 to 760 nm Infrared radiation beyond 760 nm Visible light has little biologic activity, except for stimulating the retina Infrared radiation is experienced as radiant heat Below 400 nm is the ultraviolet spectrum, divided into three bands: UVA, 320 to 400 nm UVB, 290 to 320 nm UVC, 200 to 290 nm Virtually no UVC reaches the earth’s surface, because it is absorbed by the ozone layer Exception: Australia, welders Sunburn and Solar Erythema

42. UVB is 1000 times more erythemogenic than UVA UVA is 100 times greater than UVB radiation during the midday hours Most solar erythema is cause by UVB Sunlight early and late in the day contains more UVA UVA is reflected from sand, snow, or ice to a greater degree than UVB Amount of ultraviolet exposure increases at higher altitudes, is greater in tropical regions, and temperate climates in summer Sunburn and Solar Erythema

43. Clinical signs and symptoms • Sunburn is normal cutaneous reaction to sunlight in excess of an erythema dose (the amount that will induce reddening) • UVB erythema peaks at 12 to 24 hrs after exposure • Desquamation is common about a week after sunburn even in non-blistering areas

44. Sunburn treatment • Cool compresses • Topical steroids • Topical remedy: Indomethacin 100 mg Absolute ethanol 57 ml Propylene glycol 57 ml spread widely over burned area with palms and let dry

45. Skin Types

46. Second-degree sunburn

47. Prophylaxis • Avoid sun exposure between 10 am and 2 pm • Barrier protection with hats and clothing • Sunscreen agents include UV-absorbing chemicals, and UV-scattering or blocking agents (physical sunscreens)

48. Chemical sunscreens: para-aminobenzoic acid(PABA), PABA esters, cinnamates, salicylates, anthranilates, benzophenoes) Physical agents: titanium/zinc dioxide Combinations of both Water resistant: maintaining their SPF after 40 minutes of water immersion Water proof: maintaining their SPF after 80 mins of water immersion UVA protection: sunscreens containing benzophenones or dibenzoylmethanes Apply sunscreen at least 20mins before sun exposure Sunscreens

49. Photoaging (Dermatohelioisis) • Characteristic changes induced by chronic sun exposure • Risk of developing these changes correlated with baseline pigmentation (constitutive pigmentation) and ability to resist burning and tan following sun exposure (facultative pigmentation)

50. Dermatoheliosis • Poikiloderma of Civatte: refers to reticulate hyperpigmentation with telangiectasia, and slight atrophy of sides of the neck, lower anterior neck and V of chest • Submental area is spared • Frequently presents in fair-skinned men and women in their middle to late thirties or early forties