Photodermatoses

Question 1

UVB radiation penetrates deeper into the dermis than UVA.

Answer 1

False – UVA penetrates deeper into the dermis, whereas UVB is mostly absorbed by the epidermis.

Question 2

Polymorphous light eruption (PMLE) is more common in women than men.

Answer 2

True – PMLE affects women more frequently, especially in temperate climates.

Question 3

Chronic actinic dermatitis is associated with type I hypersensitivity.

Answer 3

False – It is associated with type IV delayed-type hypersensitivity, not type I.

Question 4

Solar urticaria typically resolves within 24 hours.

Answer 4

True – Solar urticaria episodes are acute and usually resolve within 24 hours after sun exposure.

Question 5

Phototoxic reactions require prior sensitization.

Answer 5

False – Phototoxic reactions do not require prior sensitization, unlike photoallergic reactions.

Question 6

UVB radiation is more erythemogenic than UVA.

Answer 6

True – UVB has a shorter wavelength and is more effective at causing sunburn.

Question 7

Polymorphous light eruption (PMLE) typically affects sun-protected areas.

Answer 7

False – PMLE occurs on sun-exposed areas such as the chest, arms, and legs.

Question 8

Hydroa vacciniforme is a self-limited photodermatosis that resolves in adulthood.

Answer 8

True – This condition often improves or resolves in adolescence.

Question 9

Chronic actinic dermatitis is most common in young adults.

Answer 9

False – It typically affects older men with a history of atopy or contact dermatitis.

Question 10

Phototoxic reactions require a prior sensitization phase.

Answer 10

False – Phototoxic reactions occur on first exposure and do not require prior sensitization.

Question 11

Photoallergic reactions are immunologically mediated.

Answer 11

True – These reactions are delayed-type hypersensitivity reactions triggered by UV-activated antigens.

Question 12

Photopatch testing is the standard method for diagnosing phototoxic reactions.

Answer 12

False – Photopatch testing is used for diagnosing photoallergic reactions.

Question 13

Porphyrias are characterized by impaired heme biosynthesis.

Answer 13

True – They involve enzyme deficiencies in the heme synthesis pathway.

Question 14

Erythropoietic protoporphyria often presents with painful burning and swelling after sun exposure.

Answer 14

True – This is a hallmark of the disease.

Question 15

Pseudoporphyria can be differentiated from porphyria cutanea tarda by normal porphyrin studies.

Answer 15

True – Porphyrin levels are normal in pseudoporphyria.

Question 16

Solar urticaria resolves rapidly upon cessation of sun exposure.

Answer 16

True – Symptoms usually subside within an hour after removal from sunlight.

Question 17

Actinic prurigo is more common in individuals of European descent.

Answer 17

False – It is more prevalent among Native American populations.

Question 18

Photodermatoses can mimic autoimmune connective tissue diseases.

Answer 18

True – Their clinical presentations can overlap, requiring careful differentiation.

Question 19

Drug-induced photosensitivity is more commonly phototoxic than photoallergic.

Answer 19

True – Phototoxic reactions are more frequent and occur with many medications.

Question 20

The wavelength range of UVA is 290–320 nm.

Answer 20

False – UVA ranges from 320–400 nm; 290–320 nm is UVB.

Question 21

Wavelength and energy of light are directly proportional.

Answer 21

False – They are inversely proportional.

Question 22

The minimal erythema dose (MED) is used to determine individual UV sensitivity.

Answer 22

True – It is the lowest dose of UV radiation that produces redness.

Question 23

PUVA therapy uses a combination of psoralen and UVB radiation.

Answer 23

False – PUVA uses psoralen and UVA.

Question 24

Wavelengths below 290 nm (UVC) are typically filtered by the ozone layer.

Answer 24

True – UVC does not reach the Earth’s surface.

Question 25

Visible light has no impact on photodermatoses.

Answer 25

False – Some conditions like erythropoietic protoporphyria are triggered by visible light.

Question 26

Chronic actinic dermatitis often shows histologic features of spongiotic dermatitis.

Answer 26

True – Spongiosis is a common finding.

Question 27

Photo-induced lupus erythematosus may present similarly to subacute cutaneous lupus.

Answer 27

True – Both forms show photosensitivity and similar lesions.

Question 28

Phototoxic reactions are limited to sun-exposed areas.

Answer 28

True – They occur where the skin has been exposed to UV radiation.

Question 29

Broad-spectrum sunscreens protect against both UVA and UVB.

Answer 29

True – They are designed to block both ranges.

Question 30

Erythropoietic protoporphyria is associated with liver dysfunction.

Answer 30

True – Protoporphyrin can accumulate in the liver, leading to complications.

Question 31

Porphyria cutanea tarda is associated with hepatitis C infection.

Answer 31

True – Hepatitis C is a known risk factor.

Question 32

Solar urticaria is mediated by a type IV hypersensitivity reaction.

Answer 32

False – It is mediated by an immediate type I hypersensitivity response.

Question 33

Photodermatoses may be worsened by artificial light sources.

Answer 33

True – Certain bulbs emit UVA or visible light that can aggravate symptoms.

Question 34

Drug-induced photosensitivity is always reversible upon drug discontinuation.

Answer 34

False – While often reversible, some effects may persist.

Question 35

Chronic actinic dermatitis is rarely associated with contact allergens.

Answer 35

False – It is frequently associated with contact sensitivity.

Question 36

DNA repair mechanisms play no role in photoprotection.

Answer 36

False – DNA repair is crucial in preventing photocarcinogenesis.

Question 37

Photoprotection includes behavioral, physical, and pharmacologic strategies.

Answer 37

True – All three approaches help reduce UV exposure.

Question 38

Phototesting is used to determine action spectra in photodermatoses.

Answer 38

True – It helps identify the wavelengths that trigger reactions.

Question 39

Systemic antimalarials are effective in treating cutaneous lupus triggered by light.

Answer 39

True – Drugs like hydroxychloroquine are beneficial.

Question 40

Vitamin D levels can be decreased in individuals with rigorous photoprotection.

Answer 40

True – UV exposure is required for vitamin D synthesis.

Question 41

Polymorphous light eruption has a higher incidence in temperate climates.

Answer 41

True – It is more common in areas with variable sun exposure.

Question 42

Photoallergic dermatitis may persist after discontinuation of the offending agent.

Answer 42

True – The inflammatory response can continue for days or weeks.

Question 43

Phototoxic reactions typically show necrosis of keratinocytes histologically.

Answer 43

True – Sunburn cells and epidermal necrosis are common.

Question 44

Porphyrin testing is required to diagnose erythropoietic protoporphyria.

Answer 44

True – Free protoporphyrin levels are elevated.

Question 45

Tanning beds are a safe alternative to natural sunlight for patients with photodermatoses.

Answer 45

False – They emit UVA and can exacerbate conditions.

Question 46

Erythema ab igne is caused by chronic exposure to infrared radiation.

Answer 46

True – It results from repeated heat exposure.

Question 47

Polymorphous light eruption typically develops minutes after sun exposure.

Answer 47

False – It usually appears several hours after exposure.

Question 48

Artificial UV radiation is used in phototherapy for certain skin diseases.

Answer 48

True – Controlled UV light is used therapeutically.

Question 49

Actinic prurigo may present with cheilitis.

Answer 49

True – Lip involvement is common in this disorder.

Question 50

Chronic actinic dermatitis has a prolonged course and may be disabling.

Answer 50

True – It can be persistent and severely affect quality of life.

Question 51

Histologic findings in PMLE are always diagnostic.

Answer 51

False – Findings are often non-specific.

Question 52

Visible light protection is necessary in patients with lupus erythematosus.

Answer 52

True – Some patients are sensitive to visible light.

Question 53

Patients with erythropoietic protoporphyria require lifelong photoprotection.

Answer 53

True – Strict avoidance of light is essential.

Question 54

PMLE is more common in individuals with darker skin phototypes.

Answer 54

False

Question 55

Which is the most common morphology of PMLE?\nA. Bullous lesions\nB. Vesicles only\nC. Papules\nD. Telangiectatic plaques

Answer 55

C. Papules

Question 56

PMLE typically occurs within minutes of UV exposure.

Answer 56

False

Question 57

What is the best initial treatment for PMLE?\nA. Methotrexate\nB. Strict photoprotection and gradual light desensitization\nC. Systemic corticosteroids\nD. Antihistamines

Answer 57

B. Strict photoprotection and gradual light desensitization

Question 58

CAD affects both genders equally.

Answer 58

False

Question 59

Which supports a diagnosis of CAD over CTCL?\nA. CD4+ infiltrate\nB. TCR gene rearrangement\nC. CD8+ cells and negative TCR study\nD. Sezary cells

Answer 59

C. CD8+ cells and negative TCR study

Question 60

Visible light can trigger CAD.

Answer 60

True

Question 61

Which systemic therapy has recently shown promise for recalcitrant CAD?\nA. Dupilumab\nB. Adalimumab\nC. Infliximab\nD. Ustekinumab

Answer 61

A. Dupilumab

Question 62

HV usually starts in adolescence and resolves in old age.

Answer 62

False

Question 63

Which virus is implicated in HV and HV-like LPD?\nA. HSV\nB. EBV\nC. CMV\nD. HHV-6

Answer 63

B. EBV

Question 64

Classic HV differs from HV-like LPD in that it is a benign, scarring photodermatosis.

Answer 64

True

Question 65

Photoprotection is the mainstay of treatment in both classic HV and HV-like LPD.

Answer 65

True

Question 66

Actinic prurigo is most common in fair-skinned individuals in northern climates.

Answer 66

False

Question 67

Which HLA allele is associated with actinic prurigo?\nA. HLA-B27\nB. HLA-DR4\nC. HLA-A2\nD. HLA-DQ2

Answer 67

B. HLA-DR4

Question 68

Actinic prurigo typically presents with pruritic nodules and cheilitis.

Answer 68

True

Question 69

Actinic prurigo generally resolves with adolescence.

Answer 69

False

Question 70

Is PMLE most commonly triggered by visible light?

Answer 70

False – PMLE is primarily triggered by UVB and UVA radiation; visible light is rarely a trigger.

Question 71

What areas does PMLE typically affect?

Answer 71

True – These are typical sites for PMLE lesions.

Question 72

Does PMLE usually present within minutes of sun exposure?

Answer 72

False – Lesions typically appear hours after sun exposure, often delayed to the next day.

Question 73

Is PMLE more common in darker skin phototypes?

Answer 73

False – It is more commonly seen in lighter skin phototypes.

Question 74

Does PMLE tend to improve over the summer due to hardening?

Answer 74

True – With repeated exposure, symptoms may lessen (a phenomenon called “hardening”).

Question 75

Does hydroa vacciniforme typically present in adulthood?

Answer 75

False – It presents in childhood and may remit in adolescence.

Question 76

Do hydroa vacciniforme lesions resolve without scarring?

Answer 76

False – Lesions often heal with varioliform (pox-like) scarring.

Question 77

Can HV-like lymphoproliferative disorder be associated with systemic EBV-positive lymphoma?

Answer 77

True – HV-like LPD may progress to EBV+ T or NK cell lymphoma.

Question 78

Is hydroa vacciniforme primarily caused by photosensitivity to visible light?

Answer 78

False – The condition is usually induced by UV exposure, particularly UVB and UVA.

Question 79

Is rigorous photoprotection essential in the management of HV?

Answer 79

True – Sun avoidance is the mainstay of treatment.

Question 80

Does classic HV include systemic symptoms like fever and hepatosplenomegaly?

Answer 80

False – These are features of HV-like LPD, not classic HV.

Question 81

Is EBV RNA frequently found in lesional skin of HV patients?

Answer 81

True – Especially in patients with severe or systemic disease.

Question 82

Is HV more common in girls than boys?

Answer 82

False – It is slightly more common and more severe in boys.

Question 83

Can phototesting in HV induce vesicular lesions?

Answer 83

True – Monochromatic and broadband UVR testing can provoke lesions.

Question 84

Does chronic actinic dermatitis occur mostly in young women?

Answer 84

False – It is more common in older men but increasingly seen in women and people with darker skin types.

Question 85

Does CAD have a histological appearance similar to allergic contact dermatitis?

Answer 85

True – It often mimics a delayed-type hypersensitivity pattern.

Question 86

Can CAD be triggered by UVA, UVB, and visible light?

Answer 86

True – All these wavelengths may provoke the reaction.

Question 87

Does CAD usually resolve spontaneously within one year?

Answer 87

False – Resolution is slow and occurs in a minority over years.

Question 88

Is photopatch testing useful in CAD?

Answer 88

True – Helps identify photoallergic contact sensitizers.

Question 89

Do CD4+ cells predominate in CAD histology?

Answer 89

False – CD8+ T cells are typically predominant.

Question 90

# Describe

Question 91

Question 92

Question 93

Answer 93

Cutis Rhomboidalis Nuchae

Question 94

Answer 94

Erosive pustular dermatosis

Question 95

Answer 95

Multiple open comedones on the temple = Favre Racouchot syndrome

Question 96

Answer 96

Keratodelastoidosis marginalis sign of photodamage - papules and scale in a marginal distribution on the medial aspect of the forefinger and lateral aspect of the thumb