704 Fig. 1 In the mitochondrium, ferrochelatase catalyzes the for- mation of heme from protopor- phyrin IX. ALA: δ- aminolevulinic acid Glycine SuccinylCoA ALA _ Protoporphyrinogen IX Protoporphyrin IX Haem Ferrochelatase in spring and summer [10]. The symptoms include pain, burning, itching, erythema, and swelling, which can develop within minutes of sun exposure [4, 10, 13, 14]. Petechiae, purpura, and vesicles may be seen, but are uncommon [4]. Typically, children experience relief when cooling the skin with cold water or wet towels [11]. Chronic UV (ultraviolet) exposure can lead to lichen- ification, postinflammatory hyperpigmentation, and scar- ring, particularly over the knuckles and on the nose [13, 23]. Of note, the cutaneous symptoms can be discrete and barely notable in early childhood despite significant subjective discomfort including burning and stinging sensations in the skin. Here, we describe a girl with EPP with an unusual clinical course, demonstrating that parents and physicians cannot always recognize how much the patients suffer. Case report An otherwise healthy, 4-year-old Dutch Caucasian girl presented with a 1-year history of suddenly occurring severe itching and pain in the hands, feet, and nose after sunlight exposure. These sensations lasted up to 3 days, and she reported on three such incidents during the last 12 months. The symptoms developed either immediately or up to 8 h after UV exposure. Erythema or other skin manifestations were not seen. The condition worsened in the summer months and during vacations in sunny climates. Itching commenced immediately after sunlight exposure and reached a maximum at night. After a few hours, the itching changed into pain. Application of wet towels or cold baths led to partial relief, and the symptoms usually vanished spontaneously after a couple of cloudy days without intense UV exposure. Looking back, her parents also remembered that at the age of 1 year, during a summer vacation, she had suffered from an unexplained acute swelling of the hands and feet. At that time no specific Eur J Pediatr (2008) 167:703–706 diagnosis was made, besides the suspicion of an allergy. During that vacation at the sea side, the overall family life was disturbed because she was continuously agitated, cried a lot without an apparent reason, and did not sleep well. Upon physical examination in our outpatient clinic at the age of 4, she showed no skin symptoms except for few minimal excoriations on the dorsal aspects of the feet. The family history revealed eczema in the mother and atopy in the paternal grandmother, but was unremarkable regarding increased photosensitivity. Eventually, a pediatrician sug- gested the differential diagnoses polymorphic light erup- tion, warmth intolerance, or hypochondria, and the girl was treated unsuccessfully with antihistamines. Due to continuation of her complaints, a pediatric dermatologist was consulted who suspected EPP despite the absence of cutaneous manifestations. Blood porphyrin analysis revealed elevated free erythrocyte protoporphyrin (FEP) levels of 9,821 μg/l (normal 0–300 μg/l), confirming the diagnosis of EPP. Affirmative phototesting showed maximal cutaneous sensitivity at a wavelength of 400 nm (violet light). Full blood count and liver enzymes were normal. Therapeutically, strict UV light avoidance, protective sunscreens, and annual follow-up visits were advised. Still, her photosensitivity did not improve, and mild hyperpig- mentation and sores at her nose and upper lip as well as pronounced knuckles and progressive lichenification devel- oped at the age of 6. To date, she has not shown liver enzyme alterations. Discussion Here we present a girl with EPP who suffered from a significant decrease of quality of life due to severe itching and pain of the skin. Clinically, EPP is characterized by cutaneous photosensitivity manifesting early in life. Acute photosensitivity episodes include burning, stinging, and pruritus in sun-exposed skin, particularly on the nose, cheeks, and dorsal aspects of the hands, followed by erythema, edema, and wax-like scarring. Skin symptoms can occur within minutes of sun exposure, often starting early in spring time, continuing through the summer, and diminishing in fall and winter. Interestingly though, our patient did not show any visible skin lesions until the age of 6. Over the last 30 years there have been ten reports on children with EPP who developed mild to severe cutaneous photosensitivity and specific skin manifestations [1, 2, 11, 15, 19–21, 23, 30, 31]. With mild or absent visible skin symptoms, however, diagnosis may be delayed for several years or is not made at all because the discomfort experienced by the young patients is disproportionate to the objective cutaneous