It is a common eczematous photodermatosis
i.e., an itchy, inflammatory skin disorder
caused due to sun exposure persisting for
Action Spectrum- UVA, UVB, Visible light.
Allergic contact dermatitis
Drug induced photosensitivity
Air borne contact dermatitis
Photoaged and aged skin.
Presence of predominantly CD8+ cytotoxic
suppressor cells results in developing
CAD from pre existing disorders.
CAD may develop as delayed type of
hypersensitivity reaction during initial
localized photo allergic reaction to a
normal skin altered to become antigenic
by light or hapten binding to endogenous
carrier protein through UVA dependent
covalent photochemical reaction. DNA is
the prime target.
DNA of normal
Delayed type of
Itchy, confluent eczematous patches seen
over photo exposed sites
Often a sharp border at the edge of
Sparing of upper eyelids, retroauricular
and submental region, finger webs, depth
of skin creases.
Erythematous plaques with shiny infiltrated
papules may develop.
Lichenification over period of time.
Persistent light reactors
Photosensitivity Dermatitis and Eczema
Histology-chronic eczema with or without
lymphoma like changes.
Photobiologic- reduction in MED of UVB, UVA
on normal skin.
In mild cases- chronic eczema, acanthosis and
spongiosis are seen.
In severe CAD Pautrier like microabcesses
seen in epidermis.
An upper dermal dense lymphocytic
perivascular infiltration seen.
Eosinophils, macrophages, plasma cells may
In Actinic Reticuloid it resembles T cell
lymphoma except mitotic figures are less
Photo provocation is performed on uninvolved
skin. An eczematous response to UVB in majority
and to UVA,VR in less patients.
The MED of UVB is reduced in 70% & UVA in
33% of patients.
PATCH TEST and PHOTOPATCH
To detect allergens like oleoresins, compositae
Circulating Antinuclear antibodies. CD8+ sezary
cells in the absence of malignancy.
Absolute photoprotection .
Usage of broad spectrum sunscreens.
Topical steroids in mild cases.
Topical use of Tacrolimus.
In moderate to severe cases:
Azathioprine- 1.5 to 2.5 mg/kg/day
Cyclosporine- 3.5 to 5 mg/kg/day