Pentoxifylline: An effective therapy for necrobiosis lipoidica

Pentoxifylline in dermatology

BACKGROUND

Pentoxifylline was initially marketed for use in patients with intermittent claudication due to chronic occlusive arterial disease of the extremities but has since been shown to have several off-label uses in dermatology.

AIMS

The aim of this review is to increase awareness of the several applications of pentoxifylline in the field of dermatology.

METHODS

A comprehensive PubMed search was conducted in May 2022 using the following phrases "dermatology" AND "pentoxifylline." Our search period spanned 34 years from 1988 to 2022. All available literature was reviewed. Reference lists of identified articles were included. Studies were excluded if they were not in English and if the study was out of scope. Eighty-one articles were included in this review.

RESULTS

Pentoxifylline has been used to treat various dermatological conditions including peripheral vascular disease, vasculitis and vasculopathies, chilblains, pigmented purpuric dermatosis, granuloma annulare, necrobiosis, keloids, lichen sclerosis et atrophicus, scars, radiation-induced fibrosis, vitiligo, alopecia areata, leishmaniasis, and leprosy.

CONCLUSIONS

Pentoxifylline's use in dermatology is growing. However, there are limited larger studies and randomized control trials on the use of pentoxifylline in dermatology and more investigation is needed to evaluate its use for many dermatologic conditions. Pentoxifylline's unique mechanism of action as well as its good tolerability, cost-effectiveness, and minimal drug interactions make it a convenient primary or adjunctive option in many dermatological conditions.

Dermatologic manifestations of endocrine disorders

The skin serves as a window for clinicians to understand, diagnose, and monitor endocrine disease. Dermatologic manifestations of endocrinopathies contribute significantly to an individual's health and quality of life. In this review, we outline various disorders of the hypothalamic-pituitary axis, thyroid gland, pancreas, adrenal gland, and androgen axis as well as hereditary endocrine syndromes. In acromegaly, glycosaminoglycan deposition contributes to a thickening of skin and soft tissue, which manifests as coarsening and enlargement of facial and acral structures. Stimulation of the thyrotropin receptor in hyperthyroidism results in mesenchymal tissue proliferation and consequent pretibial myxedema; other associated cutaneous features include onycholysis, and hyperhidrosis. Individuals with hypothyroidism exhibit cold, dry skin and brittle hair as well as a jaundice-like appearance due to carotene excess. The cutaneous features of diabetes mellitus (DM), mediated to a large extent by hyperglycemia and hyperinsulinemia, include necrobiosis lipoidica diabeticorum (NLD), diabetic dermopathy, and acanthosis nigricans. Pediatric patients with Cushing's syndrome almost invariably present with truncal obesity and growth retardation; disruption of collagen formation and the catabolic effects of hypercortisolism result in skin atrophy and purple abdominal striae. In patients with Addison's disease, generalized hyperpigmentation, secondary to elevated levels of melanocyte-stimulating hormone (MSH), is most prominent in sun-exposed areas. Due to hyperandrogenism, individuals with polycystic ovarian syndrome (PCOS) often exhibit hirsutism, acne vulgaris, and androgenetic alopecia. In multiple endocrine neoplasia (MEN) syndromes, specific gene mutations may lead to angiofibromas, lichen amyloidosis, and ganglioneuromas. Disruptions of immune regulation result in autoimmune polyglandular syndromes (APS) and associated clinical features including chronic mucocutaneous candidiasis, vitiligo, and alopecia areata. This paper highlights the underlying pathophysiology, dermatologic manifestations, and treatment of the aforementioned endocrine disorders.