Photosensitive Disorders Dr. Abhishek De Assistant Professor, IPGMER Digital Lecture Series : Chapter 17 CONTENTS Spectrum of UV rays Fitzpatrick phototyping scale Normal cutaneous response to UV rays Immediate pigment darkening Vs delayed pigmentation Classification of photodermatologic disorders Approach to photosensitive disorders Investigation Treatment MCQs Photo quiz Spectrum of UV Rays Visible rays of sunlight : 400 nm to 700 nm. Ultraviolet rays : 400 nm to 200 nm. UV light can be UVA (400 315 nm), UVB ( nm), UVC ( nm). UVA can further be divided into UVA1 ( nm) and UVA2 ( nm). UV rays below 290 nm is virtually undetectable on earth surface. All of UVC and Majority of UVB rays are absorbed by the ozone layer. Fitzpatrick phototyping scale Skin TypeSkinHairEyePhoto Reaction Type IPale whiteBlond or redBlueAlways burns, never tans Type IIWhite, fairBlond or red Blue, green, or hazel Usually burns, tans minimally Type III Cream white Any Sometimes mild burn, tans uniformly Type IV Moderate brown BlackBlack Brown Rarely burns, always tans well Type VDark brownBlack Very rarely burns, tans very easily Type VI dark brown to black Black Never burns, tans very easily Acute and Sub acute Effects Sunburn (Acute Inflammatory Erythema) : UVB is most erythemogenic (Highest at 300 nm wavelength) Immediate Pigment Darkening Delayed Pigmentation (Tanning) Epidermal hyperplasia Immunological Changes : Alter Langerhans cell function, Increase CD8 cells, Changes Cytokine pattern Vitamin D3 Synthesis : UVB at 300 +/- 5 nm changes 7- dehydrocholesterol into pro-vitamin D3 Chronic Effect Photo-Ageing Photo-Carcinogenesis Normal Cutaneous Response to UVR Exposure Immediate Pigment Darkening vs Delayed Pigmentation (Tanning) Immediate Pigment DarkeningDelayed Pigmentation (Tanning) Occurs within seconds of exposureOccurs after hours of sun exposure Persists for 10 to 20 minutesPersists for days By UVA exposureUVB exposure More in Darker skin typeIn genetically competent individual Due to cellular redistribution of melanin and due to photo-oxidative Process Increased production of melanin Does Not protect from future sun burn Decrease sun burn Potential by 2 to 4 fold Immunologically mediated Photo-dermatoses Polymorphic Light Eruption Actinic Prurigo Hydroa vacciniforme Chronic Actinic Dermatitis Solar Urticaria Inherited Photosensitive Disorders Disorder of Defective DNA repair : Xeroderma pigmentosum, Cockayne, Trichothiodystrophy Disorder of Chromosomal Instability : Blooms syndrome, Rothmund-Thomson, Kindler Photo-aggravated dermatoses Chemical or Drug induced Photo dermatoses Classification of Photo dermatologic disorders The most common Photodermatosis Affects all races and colors. Attacks are intermittent and follows minutes to hours after sun exposure Most severe in the spring and early summer and disappears in winter. Presents most commonly as pruritic grouped erythematous papules, papulo-vesicles and plaques in photo- exposed areas. Most commonly affected areas are forearm, neck, face and dorsum of the hand. Polymorphic Light Eruption Etiopathogenesis is unknown but appears to be a delayed type of hypersensitivity to a photo-induced antigen possibly a heat shock protein. UVA and UVB both can be responsible Areas of constant solar exposure are usually spared because of hardening effect. Differential Diagnosis : Lupus erythematosus, atopic dermatitis, allergic contact dermatitis, prurigo etc. Polymorphic Light Eruption Treatment Photo-protection (Sunscreen, Protective clothing, Broad brim hat, umbrella) Topical and Oral Corticosteroid Narrow Band UVB Psoralen UVA photo-chemotherapy (PUVA) Anti-malarials Polymorphic Light Eruption Synonym : Hutchinsons summer prurigo. May be a familial or persistent form of polymorphic light eruption. Sunlight induced extremely pruritic and crusted nodular or papular eruption, mainly in photo-exposed areas. Rarely can involve covered site also. Face and distal limbs are most commonly involved. Most severe form seen in native Americans, but can affect all race. Actinic Prurigo Familial form is common, strong association with HLA DR4 is present. Eruption is worst at summer but can persists whole year. Complications : Linear or pitted scar in face (unlike PMLE which heals without scarring), cheilitis and conjunctivitis. Management : Photo-protection, PUVA, NB UVB, Thalidomide, topical Tacrolimus. Actinic Prurigo Rare photo-dermatosis. Typically starts in children. Boys are more commonly affected and have a more severe disease. Symmetrically distributed papules and plaques, can develop umbilicated vesicles, followed by hemorrhagic crusting which heals with varioliform scars. Management : Stringent photo-protection, low dose phototherapy, antimalarials, azathioprine or cyclosporine. Hydroa Vacciniforme Chronic eczematous eruption which may lead to lichenification and pseudolymphomatous lesions. Seen in elderly individual (> 50 years). More common in male. UVB, UVA or Visible rays may be involved. Photo-patch test often positive. Occasionally there can be spontaneous resolution over years. Management : Photo-protection, PUVA, antihistamines. Chronic actinic dermatosis Urticaria induced by sun exposure. Lesions appear within 10 minutes of exposure and disappear by 2 hours. More common in middle aged females. Usually caused by UVA or visible rays. Some shows spontaneous resolution. Management : Photo-protection, PUVA, antihistamines, plasmapheresis. Solar Urticaria Disorder of Defective DNA repair Xeroderma PigmentosumCockayne Autosomal Recessive Photosensitivity ++ Skin : Early onset Lentigines Skin : No pigmentary changes, thinning of hairs and skin Cancers : Melanoma, SCC, BCCCancers : No increase in malignancy Eyes : Photophobia, KeratitisEyes : Retinal degeneration Neurology : Deafness, Seizure Neurology : Microcephaly, Mental retardation, Deafness Disorder of Defective DNA repair Xeroderma PigmentosumCockayne Face : Normal Face : Loss of adipose tissue, prominent ear, dental caries Skeletal system : NormalSkeletal system : Cachectic dwarfism Action Spectrum : nmAction Spectrum : Unknown Xeroderma pigmentosum Disorder of Chromosomal Instability Bloom SyndromeRothmund-Thomson Autosomal Recessive Photosensitivity ++Photosensitivity : Transient Mutation in BLM gene (RECQL3)Mutation in RECQL4 gene Skin : Malar Erythema, CALM, areas of hypopigmentation Skin : Erythema and vesicles followed by Poikiloderma, sparse hair, hypoplastic nail, dental defect Face : Elongated face, prominent nosesFace : midface hypoplasia, saddle nose Stature : Short Disorder of Chromosomal Instability Bloom SyndromeRothmund-Thomson syndrome Intelligence : Normal Diabetes MellitusJuvenile cataract Cancer : leukemia, lymphoma, GITCancer : Osteosarcoma, SCC Reduced fertilityPituitary hypogonadism Lupus erythematosus Dermatomyositis Pellagra Pemphigus erythematosus Rosacea and acne Grovers disease Dariers disease Hailey-Hailey disease Carcinoid syndrome Atopic and Seborrheic dermatitis Photo-aggravated dermatoses Lupus erythematosus Porphyria Seborrheic dermatitis Phototoxic reaction : Happens following cutaneous or systemic exposure to a phototoxic agent and appropriate UVR Erythema, vesicles and intense burning mimic an exaggerated sunburn like reaction More commonly due to systemic exposure Photo-allergic reaction : Eczematous lesions, Most commonly related to topical photoallergens Chemical or Drug induced Photo dermatoses Some Phototoxic and Photo Allergic Agents Phototoxic AgentsPhoto Allergic Agents AmiodaroneFragrances Diuretics : Furosemide, ThiazidesNSAIDS : Diclofenac, Ketoprofen Quinolones : Ciprofloxacin, Sparfloxacin Sunscreens : Oxybenzone Tetracyclines : Doxycycline, Demeclocycline Phenothiazines : Chlorpromazine PsoralensGriseofulvin Phenothiazines : ChlorpromazineQuinine NSAIDS : Naproxen, PiroxicamQuinidine Photo Contact Dermatitis : PhotoPatch testing Suggestive of Fragrance mix Clinical Diagnosis Photo exposed areas : Face, Varea& nape of neck, dorsa of hands & feet, extensors of arms & legs (check clothing used). Spared areas : Under hair fringe, chin, nose, upper eyelids, behind ears. Morphological pattern depends on etiology. Approach to photo-sensitive disorder Depending on etiology : Connective Tissue diseases-ANA (Hep2), ANA profile Metabolic: Enzyme assay Porphyrin levels (blood, urine, stool) Chromosomal analysis, cell mutation studies, DNA repair assessment Biopsy Photo testing Photo-Patch testing Investigations Topical : Sunscreens, UVA, UVB therapy. Natural : Ozone, Melanin, Keratin. Physical : Clothing, broad rimmed hats, umbrellas. Systemic : Beta carotene, Chloroquine, Hydroxychloroquine, PUVA. Treatment : Photoprotection Removal of offending drug / chemical / contactant. Steroids (topical / systemic). Immunosuppressives (Azathioprine, Cyclosporine, Thalidomide). Treatment of causative factor Physical Reflect, scatter light Zinc oxide Titanium dioxide Ferrous oxide Types of Topical Sunscreen Chemical Absorbs light & prevents penetration through skin Anthranilates, benzophenones, cinnamates, salicylates Indian skin require broad spectrum sunscreen (Both UVB and UVA protective) with Sun protective factor (SPF) >15. Liberal and uniform application to photo exposed areas, half an hour prior to sun exposure. Repeated application needed in case of prolonged sun exposure. 1ml - Face - Female 1.5ml - Face - Male Frequent reapplication if involved in vigorous exercise, swimming. Topical Sunscreen : Key Points Q.1) Antifungal drug that may cause both phototoxic and photo allergic reaction A.Amphotericin B B.Fluconazole C.Griseofulvin D.Itraconazole Q.2) Photo patch testing is useful in following A.Photo allergic reaction B.Phototoxic reaction C.SLE D.Pellagra MCQs Q.3) PMLE - the most common photodermatosis, is rarely caused by following UV radiation : A.UVA B.UVB C.both UVA and UVB D.UVC Q.4) The following wavelengths of solar radiation are responsible of photoaging A nm B nm C nm D nm MCQs Q.5) The following may include LE like eruptions except A.Procainamide B.Hydralazine C.Macrolides D.Minocycline MCQs Q. Give differential diagnosis. Photo Quiz Q. Identify the condition Photo Quiz Thank You!