Faculty Bibliography

We present a 30-year-old woman with atopic dermatitis and ichthyosis vulgaris and a one-year history of an erythematous, scaly plaque on the dorsal surface of her right hand, which developed three years after an accidental exposure to prolonged ultraviolet C (UVC) radiation in a laboratory accident. The plaque, which was initially treated as eczematous dermatitis, was eventually identified histopathologically as squamous-cell carcinoma in situ. Although causation is not definitive, this case is the first to describe development of non-melanoma skin cancer (NMSC) in an area of skin known to be acutely exposed to UVC radiation. As UVC radiation becomes a more frequently used anti-microbial technology, UVC radiation may become a more commonly identified risk factor in the development of NMSC.

Revertant mosaicism is a naturally occurring phenomenon involving spontaneous correction of a pathogenic gene mutation in a somatic cell. It has been observed in several genetic diseases, including epidermolysis bullosa (EB), a group of inherited skin disorders characterized by blistering and scarring. Induced pluripotent stem cells (iPSCs), generated from fibroblasts or keratinocytes, have been proposed as a treatment for EB. However, this requires genome editing to correct the mutations, and, in gene therapy, efficiency of targeted gene correction and deleterious genomic modifications are still limitations of translation. We demonstrate the generation of iPSCs from revertant keratinocytes of a junctional EB patient with compound heterozygous COL17A1 mutations. These revertant iPSCs were then differentiated into naturally genetically corrected keratinocytes that expressed type XVII collagen (Col17). Gene expression profiling showed a strong correlation between gene expression in revertant iPSC-derived keratinocytes and the original revertant keratinocytes, indicating the successful differentiation of iPSCs into the keratinocyte lineage. Revertant-iPSC keratinocytes were then used to create in vitro three-dimensional skin equivalents and reconstitute human skin in vivo in mice, both of which expressed Col17 in the basal layer. Therefore, revertant keratinocytes may be a viable source of spontaneously gene-corrected cells for developing iPSC-based therapeutic approaches in EB.

Iododerma is a rare cutaneous eruption occurring after iodine administration. Nine cases of iododerma following intravenous contrast have been reported in the English-language literature, typically in patients with renal insufficiency. We report a case of iododerma in a patient with relatively unimpaired renal function who underwent serial computer tomography (CT) scans with intravenous contrast. An 81-year-old woman with stage IV lung cancer developed fever and rash following serial CT scans with iodixanol contrast media. On examination, we noted conjunctival injection, enlarged glands, oral ulcers, and erythematous papules and plaques on her forehead, arms, and legs. Random urine iodine was elevated to 106,767 μg/L (normal range, 26-705 μg/L). Skin biopsy revealed diffuse predominantly neutrophilic dermal infiltrate. The patient's clinical presentation, laboratory findings, and biopsy results were consistent with iododerma. Iododerma can occur in patients with adequate kidney function, and its presentation can include ocular and glandular symptoms, as in this case. Withdrawal of the source of iodine typically leads to resolution of symptoms.