dermatoses resulting from physical factors
DESCRIPTION
Dermatoses Resulting from Physical Factors. -Heat Injuries. -Cold injuries. -Solar injuries. - Radiodermatitis . - Presure indused diseases. Heat Injuries. Thermal Burns Electrical Burns Miliaria Erythema Ab Igne. Thermal burns: *First-degree burn: - PowerPoint PPT PresentationTRANSCRIPT
Dermatoses Resulting Dermatoses Resulting from Physical Factorsfrom Physical Factors
-Heat Injuries.-Heat Injuries.-Cold injuries.-Cold injuries.-Solar injuries.-Solar injuries.-Radiodermatitis.-Radiodermatitis.-Presure indused diseases.-Presure indused diseases.
Heat InjuriesHeat Injuries
Thermal BurnsThermal Burns Electrical BurnsElectrical Burns MiliariaMiliaria Erythema Ab IgneErythema Ab Igne
Thermal burns:
*First-degree burn: There is 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.
*Second-degree burn:*Second-degree burn:
DeepDeep
Pale and anestheticPale and anesthetic
Injury to reticular dermis Injury to reticular dermis compromises blood flow compromises blood flow and destroys and destroys appendagesappendages
Healing takes > 1 monthHealing takes > 1 month
Scarring occursScarring occurs
SuperficialSuperficial
Transudation of serum Transudation of serum causing edema of causing edema of superficial tissuessuperficial tissues
Vesicles and blebs Vesicles and blebs
Complete recovery Complete recovery without scar or blemish without scar or blemish is usualis usual
Second-Degree BurnSecond-Degree Burn
Accidental scaldAccidental scald
Splash-and-Splash-and-droplet pattern droplet pattern of an accidental of an accidental scald from hot scald from hot cup of teacup of tea
*Third degree burn:
Full-thickness tissue loss.
Skin appendages are destroyed.
There is no epithelium for regeneration.
Healing leaves a scar.
*Fourth degree burn:Destruction of entire skin and subcutaneous fat with any underlying tendons
Electrical Burns:Electrical Burns:
ContactContact- small but - small but deep, causing some deep, causing some necrosis of underlying necrosis of underlying tissuestissues
FlashFlash-burns usually -burns usually cover a large area and cover a large area and are similar to a surface are similar to a surface burn and should be tx as burn and should be tx as suchsuch
Lightning is the most Lightning is the most lethal type of strike, lethal type of strike, cardiac arrest or other cardiac arrest or other internal injuries may internal injuries may occuroccur
Electrical BurnsElectrical Burns
IndirectIndirect- burns that - burns that are either linear in are either linear in areas at which sweat areas at which sweat was present; are was present; are feathery or aborescent feathery or aborescent pattern, which is pattern, which is believed to be believed to be pathognomonic pathognomonic
MiliariaMiliaria Occlusion of eccrine sweat gland leads to retention of sweat Occlusion of eccrine sweat gland leads to retention of sweat
with failure of delivery of sweat to the skin surface.with failure of delivery of sweat to the skin surface.
Eventually backed-up pressure causes rupture of sweat Eventually backed-up pressure causes rupture of sweat gland or duct at different levels.gland or duct at different levels.
Escape of sweat into adjacent tissue produces miliaria.Escape of sweat into adjacent tissue produces miliaria.
Common in hot, humid climates. Common in hot, humid climates.
Different forms of miliaria occur depending on the level of Different forms of miliaria occur depending on the level of injury to the sweat gland.injury to the sweat gland.
1.Miliaria crystalina:-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 treatment is required.
2. Miliaria rubra:-Discrete, extremely pruritic, erythematous papulovesicles with sensation of prickling, burning, or tingling.-Site of injury is prickle cell layer.
3. Miliaria pustulosa:-Always preceded by some injury, destruction, or blocking of sweat duct.-Pustules are independent of hair follicle and sterile.-Seen in intertriginous areas, flexure surfaces of extremities, scrotum, and back of bedridden pts.
4. 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 the upper dermis.-Only seen in tropics usually following a severe bout of miliaria rubra.
Treatment:
-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.
Erythema (pigmentatio) Ab Igne “toasted skin” syndrome:-Persistent erythema or coarsely reticulated residual pigmentation.
-Produced by long-continued exposure to excessive heat without production of burn.
-It begins as a mottling caused by local hemostasis and becomes a reticulated erythema, leaving pigmentation. -No effective treatment; they may benefit from:*Bland emollients.*Kligman’s combination of 5% hydroquinone in hydrophilic ointment containing 0.1% retinoic acid and 0.1% dexamethasone may reduce unsightly pigmentation.
Cold InjuriesCold Injuries
ChilblainsChilblains
FrostbiteFrostbite
Immersion injuryImmersion injury
Chilblains:-Acute chilblains is the mildest form of cold injury, characterized by inflamed purple-pink swellings on the fingers, toes, and ears.-There is pain, itching, or burning on rewarming, caused by arteriolar and venular constriction.-Patients are usually unaware of injury until they develop burning, itching, and redness.
Treatment;*Nifedipine 20mg TID, vasodilators (nicotinamide 100 mg TID or dipyridamole 25 mg TID),pentoxifylline may be useful*Smoking strongly discouraged
Frostbite:Develops 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.
Immersion Foot SyndromesImmersion Foot Syndromes
Trench FootTrench Foot
Warm Water Immersion FootWarm Water Immersion Foot
Trench FootTrench Foot
Term derived from trench Term derived from trench warfare in World War I, warfare in World War I, when soldiers stood, when soldiers stood, sometimes for hours, in sometimes for hours, in trenches with a few inches trenches with a few inches of cold water in themof cold water in them
Results from prolonged Results from prolonged exposure to cold, wet exposure to cold, wet conditions without conditions without immersion or actual freezingimmersion or actual freezing
Tx-removal from Tx-removal from environmentenvironment
Dermatosis resulting from Dermatosis resulting from sun exposuresun exposure
Parts of solar spectrum important to photomedicine:
*Visible light 400 to 760 nm, has little biologic activity, except for stimulating the retina
*Infrared radiation beyond 760 nm, 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 nmVirtually no UVC reaches the earth’s surface, because it is absorbed by the ozone layer.
Skin TypesSkin Types
A.Sunburn and Solar Erythema:
-UVB is 1000 times more erythemogenic than UVA, so most solar erythema is cause by UVB.
-UVA is 100 times greater than UVB radiation during the midday hours.
-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.
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.
Treatment:-Cool compresses-Topical steroids-Topical remedy:Indomethacin 100 mgAbsolute ethanol 57 mlPropylene glycol 57 mlspread widely over burned area with palms and let dry
Prophylaxis:-Avoid sun exposure between 10 am and 2 pm.-Barrier protection with hats and clothing.-Sunscreen agents include UV-absorbing chemicals (chemical sunscreens:, and UV-scattering or blocking agents (physical sunscreens).
Sunscreens:1. Chemical sunscreens: para-aminobenzoic acid (PABA), PABA esters, cinnamates, salicylates, anthranilates, benzophenoes).2. Physical agents: titanium/zinc dioxide.3. 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
B. 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).
1. 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.
2.Cutis rhomboidalis nuchae (sailor’s neck or farmer’s neck): -Characteristic of long-term, chronic sun exposure.-Skin on back of neck becomes thickened, tough, and leathery and normal skin marking become exaggerated.
Favre-Racouchot syndrome :-Thickened yellow plaques studded with comedomes and cystic lesions.-Treatment is removal , retinoic acid cream, surgical removal of cysts and redundant skin.
C. C. Photosensitivity:Photosensitivity: Photosensitizers may induce an abnormal reaction in skin exposed to Photosensitizers may induce an abnormal reaction in skin exposed to
sunlight or its equivalent.sunlight or its equivalent.
Substances may be delivered externally or internally.Substances may be delivered externally or internally.
Increased sunburn response without prior allergic sensitization is called Increased sunburn response without prior allergic sensitization is called phototoxicityphototoxicity..
Phototoxicity may occur from both externally applied Phototoxicity may occur from both externally applied (phytophotodermatitis and berloque dermatitis) (phytophotodermatitis and berloque dermatitis) or or internally administered chemicals internally administered chemicals (phototoxic drug (phototoxic drug reaction)reaction)..
PhytophotosensitivityPhytophotosensitivity
Plant-induced Plant-induced photosensitivity-photosensitivity-linear linear hyperpigmentation hyperpigmentation on the face on the face following exposure following exposure to limes and to limes and sunlight.sunlight.
PhytophotosensitivityPhytophotosensitivity
Hyperpigmentation Hyperpigmentation on the dorsal on the dorsal aspect of the aspect of the hands following the hands following the use of limes and use of limes and sunlight exposure.sunlight exposure.
Phototoxic Drug Phototoxic Drug Reactions:Reactions:
Most occur from tetracyclines, nonsteroidal Most occur from tetracyclines, nonsteroidal antiinflammatory drugs, amiodarone, and antiinflammatory drugs, amiodarone, and phenothiazines.phenothiazines.
Action spectrum for all is in the UVA range.Action spectrum for all is in the UVA range.
In the case of amiodarone and chlorpromazine, In the case of amiodarone and chlorpromazine, hyperpigmentation is a well-recognized pattern of hyperpigmentation is a well-recognized pattern of phototoxicity.phototoxicity.
It causes slate blue (amiodarone) or slate gray It causes slate blue (amiodarone) or slate gray (chlorpromazine) coloration, resulting from drug (chlorpromazine) coloration, resulting from drug deposition in the tissues.deposition in the tissues.
AmiodaroneAmiodarone
Phototoxic reaction Phototoxic reaction to a nonsteroidal to a nonsteroidal antiinflammatory antiinflammatory drugdrug
Phototoxicity vs photoallergy:Phototoxicity vs photoallergy:
In the case of external contactants –In the case of external contactants –phototoxicity occurs on initial exposure, has phototoxicity occurs on initial exposure, has onset < 48 hrs, occurs in most people exposed onset < 48 hrs, occurs in most people exposed to the phototoxic substance and sunlight.to the phototoxic substance and sunlight.
Photoallergy, in contrast, occurs only in Photoallergy, in contrast, occurs only in sensitized persons, may have delayed onset, sensitized persons, may have delayed onset, up to 14 days (a period of sensitization), and up to 14 days (a period of sensitization), and shows histologic features of contact dermatitis.shows histologic features of contact dermatitis.
PhotosensitivityPhotosensitivity
Drug-induced Drug-induced photosensivity-photosensivity-photoallergic photoallergic dermatitis on sun-dermatitis on sun-exposed areas of exposed areas of an infant following an infant following topical use of topical use of hexachlorophene.hexachlorophene.
Photoallergic dermatitisPhotoallergic dermatitis
Papulovesicular Papulovesicular lesions of lesions of photoallergic photoallergic dermatitis due to dermatitis due to hexachlorophene.hexachlorophene.
Drug induced Drug induced photosensitivityphotosensitivity
The erythema is The erythema is less apparent in less apparent in black skin, but the black skin, but the involvement of the involvement of the nose in this patient nose in this patient suggests suggests phototoxicity, in phototoxicity, in this case caused by this case caused by thiazidethiazide
Drug induced Drug induced photosensitivityphotosensitivity
The backs of the The backs of the hands are the hands are the classic sites to be classic sites to be involved in light involved in light induced eruptioninduced eruption
Idiopathic Idiopathic photosensitivity:photosensitivity:1. Polymorphous Light Eruption1. Polymorphous Light Eruption Most common form of sensitivity.Most common form of sensitivity. All races and skin types affected.All races and skin types affected. Typically in first three decades.Typically in first three decades. Females outnumber males.Females outnumber males. Unknown pathogenesis.Unknown pathogenesis. Positive family history in 10-50% of pts.Positive family history in 10-50% of pts. Different morphologies seen, although in the Different morphologies seen, although in the
individual the morphology is constant.individual the morphology is constant.
PMLEPMLE
Exposed areas Exposed areas such as the backs such as the backs of the hands and of the hands and forearms are forearms are affected. affected. Ultraviolet AUltraviolet A is is mainly responsible mainly responsible and may penetrate and may penetrate window glass.window glass.
PMLEPMLE
The patchiness of the edematous papules The patchiness of the edematous papules and plaques is characteristic.and plaques is characteristic.
PMLEPMLE
The eruption is less red and confluent than a The eruption is less red and confluent than a sunburn (left).sunburn (left).
Lesions are typically papular & clustered Lesions are typically papular & clustered (right).(right).
2. Actinic Prurigo2. Actinic Prurigo
The clinical features The clinical features are somewhat are somewhat suggestive of PML, suggestive of PML, but the lesions are but the lesions are persistent, mostly in persistent, mostly in children with children with crusted papules, crusted papules, and the HLA type and the HLA type was DR4 (occurs in was DR4 (occurs in 80-90% of AP pts).80-90% of AP pts).
APAP
Severe actinic prurigo shows spread to buttocks (left)Severe actinic prurigo shows spread to buttocks (left) Arms show crusted papules that are denser distally; Arms show crusted papules that are denser distally;
they are also worse in summerthey are also worse in summer
3. Hydroa Vacciniforme3. Hydroa Vacciniforme Photodermatosis with onset in childhood.Photodermatosis with onset in childhood. Lesions appear in crops with disease free intervals.Lesions appear in crops with disease free intervals. Attacks may be preceded by fever and malaise.Attacks may be preceded by fever and malaise. Ears, nose, cheeks, and extensor arms and hands are Ears, nose, cheeks, and extensor arms and hands are
affected.affected. Within 6 hrs of exposure stinging may occur.Within 6 hrs of exposure stinging may occur. There is an early, PML-like eruption, but with vesicles There is an early, PML-like eruption, but with vesicles
around the mouth and umbilicated lesions on the around the mouth and umbilicated lesions on the nose.nose.
A later, more severe example shows vesiculation with A later, more severe example shows vesiculation with umbilication, but also marked hemorrhagic crusting.umbilication, but also marked hemorrhagic crusting.
Hydroa VacciniformeHydroa Vacciniforme
Hydroa VacciniformeHydroa Vacciniforme
Radiodermatitis:Radiodermatitis:Acute Radiodermatitis:Acute Radiodermatitis: With an “erythema dose” of ionizing With an “erythema dose” of ionizing
radiation there is a latent period of up to radiation there is a latent period of up to 24 hrs before visible erythema develops.24 hrs before visible erythema develops.
Initial erythema lasts 2-3 days but may be Initial erythema lasts 2-3 days but may be followed by a second phase beginning up followed by a second phase beginning up to 1 week after the exposure and lasting to 1 week after the exposure and lasting up to 1 month.up to 1 month.
Acute RadiodermatitisAcute Radiodermatitis(fluoroscopic induced)(fluoroscopic induced)
Chronic Radiodermatitis:Chronic Radiodermatitis: Chronic exposure to “sub erythema” doses of Chronic exposure to “sub erythema” doses of
ionizing radiation over a prolonged period will ionizing radiation over a prolonged period will produce varying amounts of damage to skin and produce varying amounts of damage to skin and underlying tissues after a variable latent period of underlying tissues after a variable latent period of several months to several decades.several months to several decades.
Telangiectasia, atrophy, and hypopigmentation with Telangiectasia, atrophy, and hypopigmentation with residual focal increased pigment (freckling) may residual focal increased pigment (freckling) may appear.appear.
Radiation Cancer:Radiation Cancer: After a latent period averaging 20 –30 yrs, After a latent period averaging 20 –30 yrs,
various malignancies may developvarious malignancies may develop Most frequent are basal cell carcinomasMost frequent are basal cell carcinomas Next frequent are squamous cell carcinomasNext frequent are squamous cell carcinomas These may occur in sites of prior radiation These may occur in sites of prior radiation
even without evidence of chronic radiation even without evidence of chronic radiation damagedamage
SCCs arising in sites of radiation therapy SCCs arising in sites of radiation therapy metastasize more frequently than purely sun-metastasize more frequently than purely sun-induced SCCsinduced SCCs
Other cancers induced by radiation: Other cancers induced by radiation: angiosarcoma, malignant fibrous histiocytoma, angiosarcoma, malignant fibrous histiocytoma, sarcomas, and thyroid carcinomasarcomas, and thyroid carcinoma
Radiation CancerRadiation Cancer
SCC developing in a chronic SCC developing in a chronic radiation ulcer on the chestradiation ulcer on the chest
Callus:Callus: Nonpenetrating, circumscribed hyperkeratosis produced by pressure.Nonpenetrating, circumscribed hyperkeratosis produced by pressure.
Occurs on parts subject to intermittent pressure (palms, soles, bony Occurs on parts subject to intermittent pressure (palms, soles, bony prominences of the joints).prominences of the joints).
Callus differs from clavus (corn) in that a callus has no penetrating Callus differs from clavus (corn) in that a callus has no penetrating central core and is a more diffuse thickening.central core and is a more diffuse thickening.
Calluses tend to disappear spontaneously when pressure is removed.Calluses tend to disappear spontaneously when pressure is removed.
Dermatosis resulting from presure:Dermatosis resulting from presure:
1. Clavus (Corns): 1. Clavus (Corns): Circumscribed, horny, conical thickenings with the base on the Circumscribed, horny, conical thickenings with the base on the
surface and the apex pointing inward and pressing on adjacent surface and the apex pointing inward and pressing on adjacent structures.structures.
Two types: hard and soft.Two types: hard and soft. HardHard: occur on dorsa of toes or on soles.: occur on dorsa of toes or on soles. SoftSoft: occur between toes, softened by macerating action of sweat.: occur between toes, softened by macerating action of sweat.
Plantar corns can be differentiated from plantar Plantar corns can be differentiated from plantar warts by paring off the surface keratin until warts by paring off the surface keratin until either the pathognomonic elongated dermal either the pathognomonic elongated dermal papillae of the wart with its blood vessels, or the papillae of the wart with its blood vessels, or the clear horny core of the corn can be visualized.clear horny core of the corn can be visualized.
2. Pressure Ulcers 2. Pressure Ulcers (Decubitus):(Decubitus):
The bedsore is a pressure ulcer produced The bedsore is a pressure ulcer produced anywhere on the body by prolonged pressure.anywhere on the body by prolonged pressure.
Caused by ischemia of underlying structures of Caused by ischemia of underlying structures of skin, fat, and muscles resulting from sustained skin, fat, and muscles resulting from sustained and constant pressure.and constant pressure.
Usually in chronically debilitated persons unable Usually in chronically debilitated persons unable to change position.to change position.
Bony prominences of body are most frequently Bony prominences of body are most frequently involved.involved.
Care and treatment:Care and treatment:
Clean wounds initially and at each dressing change via Clean wounds initially and at each dressing change via nontraumatic technique.nontraumatic technique.
Normal saline is best.Normal saline is best. Dressing selection should maintain moist environment.Dressing selection should maintain moist environment. Occlusive dressings like film and hydrocolloid are Occlusive dressings like film and hydrocolloid are
often utilized.often utilized. Surgical debridement with reconstructive procedures Surgical debridement with reconstructive procedures
may be needed (except stable heel ulcers (do not may be needed (except stable heel ulcers (do not need debridement if only a dry eschar is present).need debridement if only a dry eschar is present).
Electrical stimulation of refractory ulcers may be Electrical stimulation of refractory ulcers may be beneficial.beneficial.
3. Friction Blisters:3. Friction Blisters: Formation of vesicles or bullae occurring at Formation of vesicles or bullae occurring at
sites of combined pressure and friction.sites of combined pressure and friction. Enhanced by heat and moisture.Enhanced by heat and moisture. Examples: feet of military recruits in training, Examples: feet of military recruits in training,
palms of oarsmen not having developed palms of oarsmen not having developed protective calluses, beginning drummers protective calluses, beginning drummers (“drummer’s digits”). (“drummer’s digits”).
4. Black Heel:4. Black Heel:
-Also called -Also called talon noir ortalon noir or calcaneal petechiae.calcaneal petechiae.
-A sudden shower of -A sudden shower of minute macules occurs minute macules occurs most often on the posterior most often on the posterior edge of the plantar surface edge of the plantar surface of one or both heels.of one or both heels.
-Sometimes occurs distally -Sometimes occurs distally on one or more toes.on one or more toes.
-Black heel is seen in -Black heel is seen in basketball, volleyball, basketball, volleyball, tennis, or lacrosse playerstennis, or lacrosse players
5. Painful Fat Herniation:5. Painful Fat Herniation: Painful piezogenic pedal papules.Painful piezogenic pedal papules. Rare cause of painful feet representing fat herniations Rare cause of painful feet representing fat herniations
through thin fascial layers of weight-bearing parts of the through thin fascial layers of weight-bearing parts of the heel.heel.
These dermatoceles become apparent when wt is placed on These dermatoceles become apparent when wt is placed on the heel.the heel.
These disappear when pressure is removed.These disappear when pressure is removed. Extrusion of fat tissue together with its blood vessels and Extrusion of fat tissue together with its blood vessels and
nerves initiates pain on prolonged standing. nerves initiates pain on prolonged standing. Avoidance of prolonged standing is the only way to Avoidance of prolonged standing is the only way to
provide relief.provide relief. Majority of people experience no symptoms.Majority of people experience no symptoms.
Narcotic Dermopathy:Narcotic Dermopathy: Heroin(diacetylmorphine) is a narcotic prepared by Heroin(diacetylmorphine) is a narcotic prepared by
dissolving the heroin powder in boiling water and then dissolving the heroin powder in boiling water and then injecting it.injecting it.
Favored route is IV.Favored route is IV. Resulting in thrombosed, cordlike, thickened veins. Resulting in thrombosed, cordlike, thickened veins.
Narcotic DermopathyNarcotic Dermopathy
Subcutaeous injection (“skin popping”) can result in multiple, Subcutaeous injection (“skin popping”) can result in multiple, scattered ulcerations, which heal with discrete atrophic scarsscattered ulcerations, which heal with discrete atrophic scars