Durability of the improvement of collagen I and collagen III with the use of oral isotretinoin in the treatment of photoaging.

BACKGROUND: Oral isotretinoin (ISO) is the drug of choice for the treatment of severe acne. For photoaging treatment, ISO has been proved to be effective in some controlled and noncontrolled trials and is an alternative to topical retinoic acid (RA) therapy, which causes an expected skin irritation. OBJECTIVE: To evaluate and compare the skin remodeling in patients taking ISO 20 mg 3 times a week for 12 weeks and 12 weeks after the end of the treatment to quantify collagen I and collagen III augmentation. MATERIAL AND METHODS: Immunohistochemical studies were performed to evaluate the expression of collagen I and collagen III, metalloproteinases (MMPs) -1, -3, -7, -9, -12, and the tissue inhibitor of MMP type-1 (TIMP-1) of the skin of 20 45 to 50-year-old women through morphometry in a semiquantitative method. The inclusion criteria were facial aging 2 and 3 of Glogau's classification, with phototypes between II and V who had not entered menopause. Biopsies of the skin of the left preauricular region were performed at three different times: pre-treatment (T0), end of 12-week treatment (T1), and 12 weeks posttreatment (T2). RESULTS: Collagen fibers I and III increased with statistical significance in T1 (50.7%; P = 0.012) but not in T2 (49.7%), which in turn was higher than in T0 (47.2%) for collagen I and T1 (33.3%; P = 0.002) but not in T2 (32.7%), and also was higher than T0 (32.0%) for collagen III. MMP-9 presented a decreased activity with statistical significance in T1 (P = 0.047) and T2 (P = 0.058). MMP-1 showed a reduction in T2 only (P = 0.015). MMPs -3, -7, -12, and TIMP-1 did not present significant modification in their expressions during or after the treatment. CONCLUSIONS: Low-dose ISO is effective in remodeling the extracellular matrix (ECM). This study found that the increase of collagen occurs through the augmentation of both collagen I and collagen III fibers. With originality, it was possible to verify the durability of these fibers for at least 12 weeks. This may be related to the decrease in MMP-9 expression verified at the end of the treatment and 12 weeks posttreatment.

Histopathological analysis of chronic paronychia.

BACKGROUND: Chronic paronychia is an inflammatory process of the nail folds lasting more than 6 weeks. Clinically, there is hypertrophy and retraction of the folds and absence of the cuticle. Treatment involves clinical measures and, when there is no response or the hypertrophy of the folds is very pronounced, surgical treatment is indicated. Post-surgical histopathology is little studied in the literature. In this sense, we believe that the histopathological study is important not only for the individualized understanding of the patient's chronic disease, avoiding relapses, but also for the understanding of its pathophysiology and treatment possibilities. OBJECTIVE: To describe the histopathological changes found in biopsies of the proximal nail fold of patients with chronic paronychia undergoing surgical treatment. MATERIALS AND METHODS: A histopathological study of 16 nail folds from 6 patients after surgery was performed at 2 study centers. RESULTS: The most prevalent epidermal findings were orthokeratosis, hypergranulosis, acanthosis and spongiosis and the dermal findings were fibrosis and mononuclear inflammatory infiltrate. CONCLUSION: The histopathological study allowed us to conclude that chronic paronychia is primarily an inflammatory process, but it is not possible to conclude whether microorganisms such as Candida and bacterial cocci are part of the etiology or just secondary and opportunistic agents.