Immunologically mediated
photodermatoses
Skin – light interaction
Classification of photodermatoses
Immunologically mediate
Defective DNA repair disorders
Photoaggravated dermatoses
Chemical –drug induced photosensitivity
Case 1 
13 year old girl with itchy rash on the face and hands since yesterday .
It has been a beautiful sunny day in early spring ,spent in out door activity.
She is in perfect health , with no history of similar experience or notable history of previous ailments .
She takes no medicine , prescribed or OTC.
Her mother mentions using a new sun block.
• photosensitivity induced by exogenous agents
• SLE ,DLE
• Solar Urticaria
• Hydroa Vacciniformis
• Photoaggravated dematoses
• Erthropoetic protoporphyria
ANA
Anti-Ro/SSA La/SSB antibodies
Plasma porphyrin levels
Phototesting
Photo patch testing
Urinary amin oacid levels
Polymorphic light eruption
Juvenile sprig eruption
pathogenesis
Delayed hypersensitivity response to an endogenous cutaneous photo induced antigen
genetically determined
Continuing antigen determination following UVR exposure
• photoprotection measures
• Symptomatic treatment, including the use of topical corticosteroids, is helpful once the lesions have developed
• a short course (5-7 days) of systemic corticosteroids (usually prednisone, 0.6-1 mg/kg/d) has been shown to be helpful
Phototherapy
Beta carotene
Antimalaria
Fish oil supplements
Immunosuppressives
case2
A 9 year old boy with 2 year history of very itchy lesions on the face and distal limbs , with
summer exacerbation
Mentions papular lesions within
hours of sun exposure
His mother has typical attacks of PLE
Actinic prurigo
DDx
Atopic eczema
Prurigo nodularis
Insect bite
scabies
Erythropetic protoporphyria
treatment
Photoprotection
Topical CS
Topical tacrolimus
Phototherpy
Thalidomide
Case 3
5 year old child with recurrent tender lesions on the face and dorsal hands
Healing occurs in a few weeks with
scar formation
Hydroa vacciniformis
DDx
Porphyria
Herpes simplex
HV –like eruption with EBV
treatment
Photoprotection
Phototherapy
Beta carotene 
Antimalaria
Thalidomide
Azathioprine
cyclosporine
case4
60 year old man with 3 year history of highly pruritic lesions on the face ,neck and dorsal hands .
He has been an out door worker , otherwise healthy , on no medication .
On his medical records : a previous allergy test positive to compositae.
Chronic actinic dermatitis
DDx
Photoaggravated dermatoses
Drug- chemical induced photosensitivity
Cutaneous Lymphoma
Treatment
Strict photoprotection
Avoidance of relevant allergen
Topical and intermittent oral CS
Topical tacrolimus
Phototherapy
Cyclosporin
Azathioprine
Mycophenolate mofetil
case 5
20 year old man presents with pruritic lesions within minutes of sun exposure , which resolve over 1-2 hours .
He is otherwise healthy
He has been on oral tetracycline within the previous month.
Other types of urticaria
PLE
EPP
Drug induced photosensitivity
treatment
Non sedative anti histamines
Photoprotection
Phototherapy
Plasmaphresis, IVIG, omalizumab
• AP
