Photoallergic Contact Dermatitis (PACD) Score of Cazzaniga et al

Cazzaniga et al reported a score for the diagnosis of photoallergic contact dermatitis (PACD). The authors are from multiple institutions in Europe.

Patient selection: skin reaction

Parameters:

(1) type of skin lesions (vesicles/bullae, erythema/edema, papules, necrosis)

(2) accompanying symptoms (fever, local symptoms other than itching)

(3) area of skin involvement

(4) past medical history (disorders with photosensitivity, past history photoallergic reaction)

(5) modality of exposure to the culprit photosensitizing substance (last exposure)

(6) history of sun exposure

(7) photopatch test with the culprit substance

Parameter	Finding	Points
vesicles and/or bullae on erythematous base	no	0
	yes	2
erythema and edema persisting for >= 48 hours	no	0
	yes	1
papules	no	0
	yes	1
necrosis	no	0
	yes	-2
fever related to dermatitis	no	0
	yes	-2
local symptoms other than itching	no	0
	yes	-1
area of skin involvement	primary involvement in shaded areas	-3
	reaction limited to areas exposed to the sun or light source	1
	reaction in areas exposed to the sun or light with secondary spread to non-exposed areas	3
history of diseases associated with photosensitivity	no	0
	yes	-3
history of previous photosensitivity reaction to culprit substance	no	0
	yes	3
last exposure to culprit substance	within 1 month of onset of reaction	2
	1 to 2 months prior to onset	1
	more than 2 months prior to onset, or no prior exposure	0
history of sun exposure	occurred within 48 hours before the onset of the reaction	2
	occurred 49 hours to 2 weeks before onset of the reaction	1
	other	0
photopatch test	negative	-6
	doubtful or consistent with irritant reaction	0
	highly suggestive	9

total score =

= SUM(points to all of the parameters)

Interpretation:

• minimum score: -17

• maximum score: 23

• If data is not available on 4 or more criteria then a result is not valid.

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