Medical Care
The cornerstone of pharmacologic treatment in adult patients is 100-200 mg/d of thalidomide. [23, 38] Children aged 8-15 usually are treated with 12.5-100 mg/d. [1] Studies have shown that this drug modulates its effect on actinic prurigo through suppression of tumor necrosis factor-alpha synthesis and modulation of interferon-gamma–producing CD3+ cells. [39] Thalidomide can be gradually reduced to the minimal dose that can alleviate symptoms (eg, 25-50 mg/wk) and then reinstituted in cases of relapse. Women in their childbearing years must use at least 2 contraceptive methods because of the teratogenic potential of thalidomide. On some occasions, topical steroids or immunosuppressors are indicated, especially in acute exacerbations. Once the skin lesions remit, sunscreens should be used. [1, 38, 40]
Other medications frequently used with moderate results, because of their anti-inflammatory action, are antimalarials and pentoxifylline, [41] although these drugs are more useful as topical corticosteroid–sparing agents.
Localized symptoms such as ocular signs of severe limbitis and conjunctivitis have been successfully controlled with sustained topical therapy using 2% cyclosporine A. [34] Cyclosporine A was successfully used as a systemic treatment in a Scandinavian girl with actinic prurigo, the first native of the region with the disease to be recorded. The patient had the HLA DRB1*0407 subtype which is present in just 1% of her population. [29]
Perz et al reported the case of a 42-year-old Latino male with actinic prurigo that responded well to thalidomide. However, the patient developed severe polyneuropathy, so thalidomide was discontinued. Dupilumab was then begun at an initial 600 mg subcutaneous injection and subsequent 300 mg injections every 2 weeks with excellent control of symptoms. [42] Dupilumab was also reportedly successful in clearing actinic prurigo symptoms in a pediatric patient. [43]
Less favorable results are obtained with antihistamines, beta-carotenes, and psoralen plus UVA light.
If complications (eg, secondary infection, eczema) occur, patients can be treated with oral antibiotics or topical Burrow solution.
The need for inpatient care for patients with actinic prurigo is extremely infrequent.
Prevention
Long-term precautions are important to avoid worsening of the condition. Therefore, patients should be aware of the sunniest months of the year to reduce outbreaks.
Photoprotection is important. Explaining the nature of the disease to patients is mandatory because they must protect themselves from the sun with sunglasses, hats, umbrellas, long sleeves, high neck shirts, and appropriate clothing on a daily basis. Patients must also avoid sun exposure between 9:00 am and 6:00 pm, even during the winter.
Sunscreens are only an adjunctive treatment. They do not represent a reliable control treatment. Physical sunscreens could be better than chemical sunscreens, especially in cases where excoriation is present and a burning sensation can be elicited.
Outdoor shade is not enough to provide photoprotection. Regularly, trees reduce ultraviolet light only by half.
Staying indoors could also be unsafe because window glasses do not filter long wavelengths (UVA 315-400 nm). This is especially problematic when people who are affected work close to windows.
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Itchy plaques mainly on photoexposed areas of the face; these plaques are characteristic of actinic prurigo.
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Photodistribution of lesions over the body. Note the hypopigmented areas of the skin, which are very common after intense scratching in children.
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Multiple itchy papules coalescing into plaques on the neck. These lesions are similar to lesions of polymorphous light eruption. Note the excoriations induced by scratching.
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One third of patients are children. The nose is frequently affected. This clinical feature is useful in distinguishing it from other entities, such as atopic dermatitis.
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One half of patients have bilateral conjunctivitis. Eye protection is needed to avoid disease progression.
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About 75% of patients have cheilitis, which can take the form of solid lesions or erosions.
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A phototest with UV-B light shows reproduction of lesions on the inner aspect of the arm. The result from the phototest with UV-A light was negative.
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Histologic examination shows acanthosis, mild spongiosis, edema of the lamina propria, and a moderate-to-dense perivascular lymphocytic inflammatory infiltrate.
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A close-up view shows edema of the lamina propria as well as a lymphocytic inflammatory infiltrate in the dermis.
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Young girl with a history of atopic dermatitis and itchy, lichenified plaques on her face for the last 3 months. Atopic dermatitis with photosensitivity is the main differential diagnosis with actinic prurigo in children.
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Actinic cheilitis resulting from actinic prurigo.
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Erythematous and very itchy plaques on solar exposure areas of the face and pseudopterygium are commonly observed in actinic prurigo.
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Lichenified plaques, excoriated nodules, and atrophic scars on the dorsal aspect of hands are frequently seen in children.
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Contact dermatitis due to sunscreen in a patient with actinic prurigo.
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Impetiginous area located on the right ear lobe due to intense scratching following an acute relapse.
