1. CHRONIC ACTINIC DERMATITIS
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2. DEFINITION:
It is a common eczematous photodermatosis
i.e., an itchy, inflammatory skin disorder
caused due to sun exposure persisting for
long term.
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ETIOLOGY:
Action Spectrum- UVA, UVB, Visible light.
PREDISPOSING CONDITIONS:
 Allergic contact dermatitis
 Drug induced photosensitivity
 Endogenous eczema
 Air borne contact dermatitis
 HIV Infection
 Photoaged and aged skin.

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PATHOGENESIS:
 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.

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DNA of normal
skin cells
Altered to
become an
antigen
Delayed type of
Hypersensitivity
reaction
UV
Radiation

6. CLINICAL FEATURES:
 Itchy, confluent eczematous patches seen
over photo exposed sites
 Often a sharp border at the edge of
clothing
 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.
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VARIANTS:
 Actinic Reticuloid
 Persistent light reactors
 Photosensitivity Dermatitis and Eczema
DIAGNOSIS:
Based on
 Clinical examination
 Histology-chronic eczema with or without
lymphoma like changes.
 Photobiologic- reduction in MED of UVB, UVA
on normal skin.

9. DIFFERENTIAL DIAGNOSIS
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INVESTIGATIONS:
 Histopathology:
 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
be present.
 In Actinic Reticuloid it resembles T cell
lymphoma except mitotic figures are less
frequent.

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 PHOTO TESTING:
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
TEST:
To detect allergens like oleoresins, compositae
sunscreens etc.
 Blood tests:
Circulating Antinuclear antibodies. CD8+ sezary
cells in the absence of malignancy.

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 TREATMENT:
 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
 PUVA therapy

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