[Reticulated teleangiectatic erythema after implantation of medical devices. An increasingly occurring phenomenon?]

Reticulated telangiectatic erythema (RTE) is a rare skin reaction to extraneous materials. We present three cases in which asymptomatic persistent erythemas developed in the area of implantation after medical devices were inserted. Topical and systemic treatment did not improve the skin changes. Patch testing including applied materials showed negative results in all cases. Histological investigation of punch biopsy specimens showed moderate dilatated vessels and a slight lymphocytic infiltrate. Due to our findings and in synopsis with the clinical impression we diagnosed RTE. As RTE is asymptomatic in most cases, the devices need not be removed.

Plaque-Like Sclerodermiform Localized Mucinosis Rapidly Responsive to Topical Tacrolimus

We report the successful treatment of plaque-like sclerodermiform mucinosis using tacrolimus ointment topically. We present a 70-year-old male with a large chronic erythema and hardening of the nuchal skin and shoulder area. Subjective symptoms were a moderate pruritus and a rather disabling stiffness. A biopsy specimen revealed typical features of lichen myxedematosus. In a subsequent clinical examination, no associated illnesses such as hypothyroidism or gammopathy were found. Since no established therapy exists for this condition, and as there was a lack of response to potent topical glucocorticosteroids, tacrolimus 0.03% ointment was used off-label twice daily. Surprisingly, this resulted in a rapid, almost complete clearance of the skin within three weeks of treatment.

Chemical short range order obtained from the atomic pair distribution function

Many crystalline materials show chemical short range order and relaxation of neighboring atoms. Local structural information can be obtained by analyzing the atomic pair distribution function (PDF) obtained from powder diffraction data. In this paper, we present the successful extraction of chemical short range order parameters from the x-ray PDF of a quenched Cu3Au sample.

FGFR3 and PIK3CA mutations in stucco keratosis and dermatosis papulosa nigra

BACKGROUND

Stucco keratosis (STK) and dermatosis papulosa nigra (DPN) are referred to as variants of seborrhoeic keratosis. However, the genetic alterations involved in the pathogenesis of these benign tumours are unknown.

OBJECTIVES

Because FGFR3 and PIK3CA mutations have been reported to be involved in the pathogenesis of seborrhoeic keratosis, we analysed whether these mutations are also present in STK and DPN. Methods A SNaPshot multiplex assay was used for analysis of 11 previously described FGFR3 hotspot mutations. PIK3CA mutations were analysed by a SNaPshot assay covering five PIK3CA hotspot mutations.

RESULTS

Five STK and two DPN samples were analysed. Three of five STK samples revealed a PIK3CA mutation (E542K, E545K), but no FGFR3 mutation was found. In contrast, both DPN samples harboured an FGFR3 mutation (R248C, S249C) but no PIK3CA mutation. Control tissues available for three samples did not show PIK3CA or FGFR3 mutations, excluding germline mutations and indicating a strong genotype-phenotype correlation between the mutation and the lesion.

CONCLUSIONS

These results indicate that FGFR3 and PIK3CA mutations are involved in the pathogenesis of STK and DPN. The molecular genetic findings furthermore support the concept that both skin lesions are specific variants of seborrhoeic keratosis, sharing a common genetic background.

FGFR3 and PIK3CA mutations are involved in the molecular pathogenesis of solar lentigo

BACKGROUND

Solar lentigines (SL) are frequent benign skin lesions appearing on sun-exposed areas especially in elderly people and therefore represent a hallmark of (photo)aged skin. It has been proposed that SL may subsequently evolve into adenoid seborrhoeic keratosis (SK). However, little is known about the genetic basis of SL. In human SK, FGFR3 and PIK3CA mutations have recently been identified.

OBJECTIVES

To analyse SL for potential FGFR3 and PIK3CA mutations.

METHODS

We screened 30 SL for FGFR3 mutations using a SNaPshot multiplex assay. For PIK3CA mutations we used direct sequencing of exon 9 and a SNaPshot assay for the H1047R hotspot mutation (exon 20). Because psoralen plus ultraviolet A (PUVA) lentigines show the V600E BRAF hotspot mutation, we additionally investigated this mutation in SL by allele-specific polymerase chain reaction.

RESULTS

FGFR3 mutations were detected in five of 30 (17%) SL and PIK3CA mutations in two of 28 (7%) SL. None of 28 SL available for BRAF analysis revealed the V600E mutation.

CONCLUSIONS

Our results suggest that FGFR3 and PIK3CA mutations are involved in the pathogenesis of SL. The occurrence of these mutations in both SL and SK suggests a common genetic basis. Our findings furthermore substantiate previous speculations that UV exposure may be a causative factor for FGFR3 and PIK3CA mutations in human skin.