Polymorphous light eruption in Child
Alerts and Notices
SynopsisPolymorphous light eruption (PMLE), or polymorphic light eruption, is a common acquired cutaneous disorder that is characterized by a pathological response to ultraviolet radiation (UVR). Erythematous papules, vesicles, and plaques (hence the name "polymorphous") develop minutes to hours after exposure to UVR, such as sunlight or a tanning bed. The eruption is often pruritic. It is nonscarring and photodistributed. Systemic symptoms such as fever, malaise, headache, myalgias, and arthralgias are usually absent. While lesions can last up to several weeks, most resolve within several days.
Juvenile spring eruption is considered a subtype of PMLE that occurs most frequently in boys and young men. Juvenile spring eruption is characterized by papules and vesicles on the helices of the ears. Cases generally occur in the late winter and early spring.
PMLE is most commonly seen in women with lighter skin phototypes aged 20-30, but it can occur in either sex, all ages, and all ethnicities. Approximately 20% of cases of PMLE present during childhood. Attacks most commonly occur during the spring and early summer months, especially after the first sun exposure of the season, and disappear during the winter.
The etiology of PMLE is not well understood. One theory is that UVR modifies antigens in the skin of PMLE patients to make them immunogenic. There are also data to suggest that PMLE involves a type IV delayed-type hypersensitivity reaction. The action spectrum for PMLE is UVA in most cases, but UVB and both UVA and UVB may also incite the response.
Although the condition frequently recurs, the tendency toward the development of PMLE and the severity of the eruption diminish with repeated sunlight exposure. This phenomenon is termed "hardening." As the summer proceeds, it has been observed that the incidence of new eruptions decreases. Prophylactic phototherapy supports this concept of hardening or tolerance.
Despite the variability of presentations, individual patients tend to experience the same clinical manifestations with each episode.
L56.4 – Polymorphous light eruption
238525001 – Polymorphic light eruption
Differential Diagnosis & Pitfalls
- Systemic lupus erythematosus – Check for circulating antinuclear antibodies (ANA) and other associated lupus antibodies; direct immunofluorescence will be positive; skin lesions can be located on sun-exposed and sun-protected areas (in contrast to PMLE, which is primarily in sun-exposed sites).
- Solar urticaria – Shorter time to onset of eruption with urticarial plaques lasting 1-2 hours.
- Erythema multiforme – Characteristic target lesions; systemic symptoms are prominent (in contrast to PMLE, where fever, malaise, nausea, and headache are rare).
- Hydroa vacciniforme
- Porphyria cutanea tarda – Will have abnormal porphyrin profile (elevated urine uroporphyrin and stool isocoproporphyrin).
- Erythropoietic protoporphyria – Lesions are very painful, and there is an elevated red blood cell protoporphyrin concentration.
- Photoallergic drug reaction – Investigate for drug history; not seasonally associated and does not improve over time.
- Phototoxic drug reaction
- Airborne contact dermatitis
Patient Information for Polymorphous light eruption in Child
OverviewPolymorphous light eruption is a reaction seen on the skin of people sensitive to sun exposure. This rash most often consists of multiple pink or red bumps or raised patches, but there may also be blisters or splotches. The rash is often itchy.
The reaction develops within minutes to hours after being in the sun. The first exposure to sunlight after winter usually causes the worst rash of the year, and the rash may occur every year at this time.
Most lesions will go away within several days and will not leave a scar.
Who’s At RiskPolymorphous light eruption is most common in women in their 20s with light skin, but it can affect all sexes, ages, and ethnicities.
People sensitive to sunlight may develop this rash when they are first exposed to the sun after the winter, such as visitors to tropical locations.
Signs & SymptomsThis skin rash can look like pinkish-red bumps, blisters, or splotches.
Self-Care GuidelinesPrevention is key. Avoid spending time in the sun, especially in the middle of the day. Use a broad-spectrum sunscreen and wear protective clothing when outdoors in the sun.
An over-the-counter anti-itch cream with hydrocortisone may help calm the rash. Cold compresses and cool baths may also relieve itching.
When to Seek Medical CareMost people do not seek medical care for polymorphous light eruption. If the reaction is severe and does not go away after several days, consult your medical provider.
TreatmentsYour physician or dermatologist may prescribe topical corticosteroid cream.
Antihistamines such as Benadryl may reduce itching.
If the reaction is severe, corticosteroid pills (like Prednisone) may be prescribed.
Polymorphous light eruption in Child