Cutaneous disorders characterized by elastolysis or loss of elastic tissue

Acquired cutis laxa secondary to acute generalized exanthematous pustulosis: A case report and mini-review of literature

Cutis laxa presents as loose redundant skin folds and loss of dermal elastic tissue. Acquired cutis laxa (ACL) is characterized by later onset. It has been reported in association with various kinds of neutrophilic dermatoses, drugs, metabolic disorders, and autoimmune disorders. Acute generalized exanthematous pustulosis (AGEP) is usually classified as a severe cutaneous adverse reaction characterized by T cell-mediated neutrophilic inflammation. We previously reported a mild case of AGEP caused by gemcitabine in a 76-year-old man. Here, we report a case of ACL secondary to AGEP in this patient. He developed AGEP 8 days after gemcitabine administration. Four weeks after beginning chemotherapy, his skin had become atrophic, loose, and darkly pigmented in areas previously affected by AGEP. Histopathological examination revealed edema and perivascular lymphocytic infiltration but no neutrophilic infiltration in the upper dermis. Elastica van Gieson staining showed that the elastic fibers in all layers of the dermis were sparse and shortened. Electron microscopy showed elevated numbers of fibroblasts and altered elastic fibers with irregular surfaces. Finally, he was diagnosed with ACL secondary to AGEP. He was treated with topical corticosteroids and oral antihistamines. Skin atrophy decreased over 3 months. We summarize 36 cases (including our case) with ACL secondary to neutrophilic dermatosis. We discuss these clinical manifestations, causative neutrophilic disorders, treatments, and outcomes. The mean age of patients was 3.5 years. Five patients had an aortic lesion as systemic involvement. The most common causative neutrophilic disorders were Sweet syndrome (24 cases), followed by urticaria-like neutrophilic dermatosis (11 cases). There were no cases of AGEP except for our case. Although treatment for ACL secondary to neutrophilic dermatosis, such as dapsone, oral prednisolone, adalimumab, and plastic surgery were reported, ACL is generally refractory and irreversible. Our patient was considered reversibly cured due to the absence of continuous neutrophil-mediated elastolysis.

3D-printed scaffold composites for the stimuli-induced local delivery of bioactive adjuncts

Polysaccharide scaffolds have been successfully employed to reconstruct environments that sustain skin tissue regeneration after injuries. Three-dimensional (3D) advanced additive manufacturing technologies allow creating scaffolds with controlled and reproducible macro- and micro-structure that improve the quality of the restored tissue to favor spontaneous repair. However, when persistent inflammation occurs, the physiological tissue healing capacity is reduced, like in the presence of pathologies like diabetes, vascular diseases, chronic infection, and others. In these circumstances, the bioavailability of therapeutic adjuncts like the growth factors in addition to the standard treatments represents undoubtedly a promising strategy to accelerate the healing of skin lesions. Precisely designed polysaccharide scaffolds obtained by 3D printing represent a robust platform that can be further implemented with the controlled delivery of bioactive adjuncts. Human elastin-like polypeptides (HELPs) are stimuli-responsive biopolymers. Their structure allows the integration of domains endowed with biological functionality, making them attractive compounds to prepare composites with smart properties. In the present study, 3D-printed alginate and chitosan scaffolds were combined with the HELP components. The HELP biopolymer was fused to the epidermal growth factor (EGF) as the bioactive domain. Different constructs were prepared and the stimuli-responsive behavior as well as the biological activity were evaluated, suggesting that these smart bioactive composites are suitable to realize multifunctional dressings that sustain the local release of therapeutic adjuncts.

Engineering Microneedle Patches for Improved Penetration: Analysis, Skin Models and Factors Affecting Needle Insertion

Transdermal microneedle (MN) patches are a promising tool used to transport a wide variety of active compounds into the skin. To serve as a substitute for common hypodermic needles, MNs must pierce the human stratum corneum (~ 10 to 20 µm), without rupturing or bending during penetration. This ensures that the cargo is released at the predetermined place and time. Therefore, the ability of MN patches to sufficiently pierce the skin is a crucial requirement. In the current review, the pain signal and its management during application of MNs and typical hypodermic needles are presented and compared. This is followed by a discussion on mechanical analysis and skin models used for insertion tests before application to clinical practice. Factors that affect insertion (e.g., geometry, material composition and cross-linking of MNs), along with recent advancements in developed strategies (e.g., insertion responsive patches and 3D printed biomimetic MNs using two-photon lithography) to improve the skin penetration are highlighted to provide a backdrop for future research.

Elastophagocytosis and interstitial granulomatous infiltrate are more common in extragenital vs genital lichen sclerosus

BACKGROUND

Genital and extragenital lichen sclerosus (LS) share similar histopathologic features. A recent small series documented elastophagocytosis uniquely in extragenital LS. We evaluated a larger series of LS for elastophagocytosis, elastic fiber loss, and other histopathologic features. We evaluated matrix metalloproteinase (MMP) expression to determine if these proteins play an etiologic role.

METHODS

Genital (n = 42) and extragenital (n = 41) LS biopsies were examined for histopathologic features, elastic fiber alteration (Verhoeff van Gieson staining), and MMP-2 and MMP-9 expression (immunohistochemistry).

RESULTS

Elastophagocytosis and an interstitial granulomatous pattern were significantly more common in extragenital LS than genital LS (43.9% vs 4.7% and 56.1% vs 9.5%). Extragenital LS had mild/focal elastic fiber loss (43.9%), while genital LS had moderate (61.9%) or marked (19%) loss. MMP-9 was diffusely expressed in histiocytes in both types of LS (genital 97.5%; extragenital 100%). Weak MMP-2 expression was seen in genital (58%) and extragenital (55%) LS.

CONCLUSIONS

Extragenital LS, but not genital LS, frequently exhibits elastophagocytosis and interstitial granulomatous infiltrate, and these patterns could contribute to elastic fiber destruction in extragenital LS. While MMP-2 and MMP-9 expression are common in LS, expression did not significantly differ depending on anatomic site and thus is unlikely to explain observed histopathologic differences.