17 - 96 - SOLAR URTICARIA

Question 1

Answer 1

Solar Urticaria

Question 2

Answer 2

SolU is characterized by erythema and itchy wheals that develop rapidly at skin sites exposed to sun or artificial light (Fig. 96-1). Light-exposed skin first shows diffuse erythema, followed by whealing associated with itch and/or, less frequently, burning and stinging. Wheals in SolU generally develop within a few minutes up to 1 hour of exposure and disappear usually within 1 hour and after a maximum of 24 hours of cessation of exposure, without leaving visible changes of the skin.

Question 3

True or False: SolU typically affects skin areas that are normally shielded by clothing and it spares skin sites that are frequently exposed to light such as the hands and the face

Answer 3

TRUE

presumably because chronically sun-exposed areas show “hardening” or tolerance

Question 4

Phototesting is done with the help of solar simulators with filters (UVA and UVB) or monochromators (UVA and UVB, visible light) separately for UVA at 6 J/cm, 2 UVB at 60 mJ/cm, 2 and visible light. The test is considered positive if _______

Answer 4

test site exhibits a palpable and clearly visible itchy wheal and flare reaction at 10 minutes after phototesting

Question 5

Question 6

Question 7

Skin lesions: Papules, papulovesicles, eczematous appearance; occur within hours to days after UV exposure (not within minutes); resolve within several days (not minutes to hours).

May spare face and hands (hardening).

Answer 7

Polymorphic light eruption

Question 8

Skin lesions: Occur within days to weeks after UV exposure (not within minutes); resolve within weeks (not minutes to hours). ANAs are positive.

Skin lesions with wheallike appearance.

Answer 8

Lupus erythematosus

Question 9

Skin lesions: No wheals; occur within hours to days after UV exposure (not within minutes); resolve within several days (not minutes to hours).

Answer 9

Photoexacerbated eczema (atopic, seborrheic)

Question 10

Skin lesions: No wheals; occur within hours to days after UV exposure (not within minutes); resolve within several days (not minutes to hours). Photoallergic contact dermatitis: Photopatchtest is positive.

Answer 10

Photoallergic/phototoxic contact dermatitis

Question 11

First symptoms in early childhood and lifelong persistence. Skin (lesions) is/are painful/ burning but not itchy. The pain/burning often persists for hours to days. Elevated levels of protoporphyrin in erythrocytes.

Onset within minutes after UV exposure. Skin lesions may be wheallike.

Answer 11

Erythropoietic protoporphyria

Question 12

Increased skin vulnerability in UV-exposed areas. Skin lesions comprise blisters, erosions, scars, milia, hyper- and hypopigmentation, hypertrichosis, elastosis (but not wheals). Elevated porphyrin levels in urine. Liver enzymes frequently elevated.

Answer 12

Porphyria cutanea tarda

Question 13

Patient uses medication. Skin lesions: Occur within hours to days after UV exposure (not within minutes); resolve within several days (not minutes to hours).

Answer 13

Drug or chemical photosensitivity

Question 14

Phototesting is negative; heat testing is positive.

Signs/symptoms identical to SolU.

Answer 14

Heat urticaria

Question 15

Answer 15

Treatment with nonsedating H1 antihistamines at standard dose is the recommended first-line treatment. Evidence for the efficacy and safety of antihistamine treatment in SolU comes from controlled and uncontrolled studies, 19,20 case series and reports, as well as clinical experience. In case of insufficient response to treatment with a standard-dosed nonsedating second-generation antihistamine, doses should be increased up to 4-fold. This recommendation is largely based on the results of studies of other forms of inducible urticaria. Antihistamines work, but not in all patients. Updosing is needed in many.

Treatment with omalizumab, a monoclonal antibody directed against IgE, is recommended in patients who do not achieve sufficient control with the combined use of sunscreens and antihistamine treatment. For omalizumab, a complete or partial response in doses of up to 450 mg every 4 to 8 weeks has been reported in several case studies. 21-30 The best evidence comes from a recent open-label French multicentric Phase II study with 10 patients 31 that shows that omalizumab, at 300 mg every 4 weeks, is of benefit in half of the treated patients. Two reports showed no improvement.

Other therapies that have been reported to be effective in some but not all patients include ciclosporin34 and intravenous high-dose immunoglobins.35,36 Afamelanotide, an alpha-MSH analog and melanocortin receptor agonist recently licensed for the treatment of erythropoietic protoporphyria, was shown to protect SolU patients from the development of signs and symptoms in a small open-label study.

Question 16

1. Maridar, a 30-year-old female beach vlogger, noted development of diffuse erythema followed by pruritic wheals with burning sensation a few minutes after sun exposure. The lesions usually resolves in 1 hour with no visible changes in the skin, but was noted to be recurrent. Based on your diagnosis. Which of the following statements is/are true?

a. The disease only affects females with peak age of onset at 20-40 years

b. Affects skin that is normally shielded by clothing, spares skin sites that is frequently exposed to light

c. The disease does not include constitutional signs and symptoms such as malaise, nausea, dizziness, headache, wheezing

d. Testing for porphyria and SLE such as: ANA, ENA, blood and urine stool testing for porphyrins should be done

e. B and D

2. In relation to question 1, phototesting is essential in confirming the diagnosis. T/F?
3. In relation to question 1, you would advise the patient the following except?

a. Anaphylactic shock may occur, which is rarely fatal

b. Sensitivity can be due to UVA and visible light, and less commonly UVB

c. 50% of patients will experience complete spontaneous remission within 5 years of disease onset

d. Sedating antihistamines is the first line treatment

4. In relation to question 1, histopathology may show:

a. mild acanthosis, exocytosis of lymphocytes, spongiosis, and mild basilar vacuolar degeneration.23 In the dermis, there is a moderate lymphohistiocytic superficial and middermal perivascular infiltrate, along with papillary dermal edema.

b. Within the first hours after elicitation, vasodilation, edema, perivascular neutrophils and eosinophils in the upper dermis. After 24 hrs, mononuclear cells are the dominating infiltrating cells

c. Early histologic changes include intraepidermal vesicle formation with spongiosis and subsequent focal epidermal keratinocyte necrosis. There is a dermal perivascular neutrophil and lymphocyte infiltrate.

d. 5% to 20% of infiltrating lymphocytes may show evidence of EBV integration on in situ hybridization

Answer 16

Answer B and D:

A- Affects BOTH genders and shows female preponderance, peak age of onset at 20-40 years (p 1651) B- Affects skin that is normally shielded by clothing, spares skin sites that is frequently exposed to light – correct!

C- Generalized signs and symptoms include malaise, nausea, headache, wheezing, dyspnea, loss of consciousness and even anaphylactic shock (p 1650) D- True p 1652

2. true
3. Answer: D

A. True – p. 1650

B. True – p. 1651

C. True – p. 1652

4. Answer: B

a. Actinic prurigo

b. SolU p 1652

c. Hydroa Vacciniforme

d. Hydroa Vacciniforme

Question 17

Light-induced angioedema may occur in SolU

a. True

b. False

Answer 17

True

Question 18

defined by the appearance of a whealing response within minutes of exposure to sunlight

Answer 18

Solar urticaria (SolU)

Question 19

secondary Solar urticaria may be caused by?

Answer 19

cutaneous porphyria or systemic lupus erythematosus (SLE)

Question 20

Wheals in SolU generally develop within a few minutes up to ______ hour of exposure and disappear usually within ____ hour and after a maximum of ____ hours of cessation of exposure, without leaving visible changes of the skin.

Answer 20

few minutes up to 1 hour of exposure and disappear usually within 1 hour and after a maximum of 24 hours of cessation of exposure

Question 21

Where are the areas of predilection of solar urticaria?

Answer 21

SUN PROTECTED AREAS

SolU typically affects skin areas that are normally shielded by clothing and it spares skin sites that are frequently exposed to light such as the hands and the face, presumably because chronically sun-exposed areas show “hardening” or tolerance.

Question 22

what wavelengths of UVR most commonly induce solar urticaria?

Answer 22

1. UVA (320 to 400 nm),
2. visible (400 to 600 nm),
3. less commonly UVB (280 to 320 nm)
4. rarely, infrared (>600 nm) radiation

Question 23

T/F.

Persons with FST I and II presents with more severe solar urticaria.

Answer 23

False

There appears to be no influence of the skin type on the occurrence or severity of SolU.

Question 24

How do you do phototesting

Answer 24

Phototesting is done with the help of solar simulators with filters (UVA and UVB) or monochromators (UVA and UVB, visible light) separately for UVA at 6 J/cm, 2 UVB at 60 mJ/cm, 2 and visible light. The test is considered positive if the test site exhibits a palpable and clearly visible itchy wheal and flare reaction at 10 minutes after phototesting.

Question 25

mean duration of SolU

Answer 25

5 to 7 years

Question 26

if positive for phototesting, what should you test next?

Answer 26

Threshold testing

Threshold testing determines the minimal urticarial dose, a marker of disease activity and response to therapy.

Question 27

recommended first-line treatment for SolU

Answer 27

nonsedating H1 antihistamines at standard dose