17 - 97 - PHOTOTOXICIY AND PHOTOALLERGY Flashcards
occurs in anyone exposed to sufficient doses of phototoxic agent and UV radiation; it usually manifests as an exaggerated sunburn reaction
Phototoxicity
immune reaction to a UVA-modified chemical, commonly topical sunscreen agents and antimicrobials in the United States and the United Kingdom, and topical nonsteroidal antiinflammatory agents in Europe.
It presents as eczematous eruption on sun-exposed areas.
Photoallergy
result of direct tissue injury caused by the phototoxic agent and radiation. It can occur in all individuals exposed to adequate doses of the agent and the activating wavelengths of radiation
Phototoxicity
type IV delayed hypersensitivity response to a molecule that has been modified by absorption of photons
photoallergy
Most of the photosensitivity induced by systemic medications are
phototoxicity
induced by topical agents
photoallergy
Phototoxic Agents
Phototoxic Agents
Photosensitizing Agent
Asymptomatic blue-gray pigmentation on sunexposed areas is associated with exposure to several agents namely, _____
amiodarone, chlorpromazine, clozapine, imipramine and, less commonly, desipramine
most commonly reported causative agent of pseudoporphyria (The development of porphyria cutanea tarda–like cutaneous changes of skin fragility, vesicles, and subepidermal blisters is associated with several phototoxic agents)
Naproxen
ACCELERATED PHOTOINDUCED CHANGES has been uniquely described with what drug
voriconazole
In sensitized individuals, exposure to the photoallergen and sunlight results in the development of a pruritic, eczematous eruption within 24 to 48 hours after exposure
PHOTOALLERGY
True or False: In photoallergy, the presence of both photoallergen and the activating wavelengths of radiation (UVA) are required
TRUE
Vesicular and bullous eruptions are most commonly associated with
phototoxicity
eczematous eruptions strongly suggest
photoallergy
associated with a burning sensation
phototoxicity
associated with pruritus
photoallergy
necrotic keratinocytes are commonly seen in
phototoxicity
spongiotic dermatitis is associated with
photoallergy
Causative agents of photo-onycholysis, except (P.1658)
a. Doxycycline
b. Ciprofloxacin
c. Aripiprazole
d. Terbinafine
D
Drugs that cause slate-gray pigmentation due to drugmetabolite melanin complex, except (P. 1658)
a. Amiodarone
b. Clozapine
c. Minocycline
d. Imipramine
C
MC causative agent of pseudoporphyria (P. 1658)
a. Amiodarone
b. Cyclosporine
c. Naproxen
d. Voriconazole
C
MC causative agent of accelerated photo-induced changes. (P. 1661)
a. Amiodarone
b. Cyclosporine
c. Naproxen
d. Voriconazole
D
on phototesting, a substance has (+) reaction only at irradiated site. This is diagnosed as: (P. 1664)
a. Photoallergy
b. ACD
c. Photoallergy and ACD
d. Irritant reaction
A
on phototesting, a substance has (+) reaction on both covered and irradiated sites. This is diagnosed as: (P. 1664)
a. Photoallergy
b. ACD
c. Photoallergy and ACD
d. Irritant reaction
B
on phototesting, a substance has (+) reaction on both covered and irradiated sites but with higher intensity at the irradiated site. This is diagnosed as: (P. 1664)
a. Photoallergy
b. ACD
c. Photoallergy and ACD
d. Irritant reaction
C
on phototesting, a substance has (+) reaction consisting of a well-defined erythema that resolves (P. promptly. This is diagnosed as: (P. 1664)
a. Photoallergy
b. ACD
c. Photoallergy and ACD
d. Irritant reaction
D
This substance is an exception to the normal kinetics of acute phototoxicity since acute response first appears after 24 hours and peaks at 24-72 hours (P. 1657)
a. PUVA
b. MAL
c. Fluorescein
d. Tar
A
this part of the nail serves as a lens to focus energy in cases of photo-onycholysis (P. 1658)
a. Nail plate
b. Nail bed
c. Nail matrix
d. Lunula
A
what type of UVR usually cause photosensitivity
UVA
PHOTODISTRIBUTED TELANGIECTASIA is associated with what drugs
calcium channel blockers, including nifedipine, amlodipine, felodipine, and diltiazem, with the antibiotic cefotaxime, and with the antidepressants venlafaxine and escitalopram
LICHENOID PHOTOSENSITIVE ERUPTION is associated with what drugs
doxycycline, capecitabine
These drugs induce exaggerated UV response as a result of their irritant effect on the skin
Fluorouracil and retinoids
