Postoperative permanent pressure alopecia

Pressure and Skin: A Review of Disease Entities Driven or Influenced by Mechanical Pressure

Skin perceives and reacts to external mechanical forces to create resistance against the external environment. Excessive or inappropriate stimuli of pressure may lead to cellular alterations of the skin and the development of both benign and malignant skin disorders. We conducted a comprehensive literature review to delve into the pressure-induced and aggravated skin disorders and their underlying pressure-related mechanisms. Dysregulated mechanical responses of the skin give rise to local inflammation, ischemia, necrosis, proliferation, hyperkeratosis, impaired regeneration, atrophy, or other injurious reactions, resulting in various disease entities. The use of personal devices, activities, occupations, weight bearing, and even unintentional object contact and postures are potential scenarios that account for the development of pressure-related skin disorders. The spectrum of these skin disorders may involve the epidermis (keratinocytes and melanocytes), hair follicles, eccrine glands, nail apparatuses, dermis (fibroblasts, mast cells, and vasculature), subcutis, and fascia. Clarifying the clinical context of each patient and recognizing how pressure at the cellular and tissue levels leads to skin lesions can enhance our comprehension of pressure-related skin disorders to attain better management.

Pressure alopecias: A review

Pressure-induced alopecias (PAs) are an infrequent group of scarring and nonscarring alopecias that occur after ischemic obstruction of capillaries that leads to circumscribed areas of hair loss. Initially described after prolonged surgeries or immobilization, type 1 PA occurs after sustained external pressure to the skin, mainly the scalp prominences. Alopecia induced by cosmetic procedures, referred in this review as type 2 PA, is reported with increased frequency in literature and predominantly emerges from pressure exerted by the volume of injectables. It is important to differentiate type 2 PA from vascular occlusion-induced alopecia because they represent distinct entities. Clinically, PA may present with erythema, swelling, and tenderness; however, alopecia might be the sole manifestation. Crusts and ulceration are associated with a worse outcome and a higher risk of scarring alopecia. Prompt diagnosis is paramount to prevent complications. Trichoscopy, although considered nonspecific, may provide relevant clues for an accurate diagnosis. Hair regrows in most cases, but prognosis depends on ischemia severity and timely treatment with reperfusion therapies or mobilization. Treatment of hair loss is usually not necessary because the disease in most cases is self-limited and reversible. The role of topical minoxidil and corticosteroids remains unknown.

Trichoscopic Findings in Pressure Alopecia: Report of Two Cases and Review of the Literature

Pressure alopecia (PA) is an uncommon type of hair loss due to ischemic changes of the scalp, as a result of prolonged immobilization. Clinically, it often appears within the 1^st month of the trigger and tends to resolve spontaneously within 4 months. If the duration of the immobilization is longer, irreversible alopecia can be developed. Trichoscopy is usually nonspecific, being black dots, broken, and dystrophic hairs the most frequent findings. However, yellow dots and thin hairs have also been reported. We herein present two patients with PA, one with a recent development and another one with a long-lasting alopecia. Both of them showed keratotic follicular plugs and thin hairs as the main trichoscopic findings.

Choosing an optimal headrest for preventing postoperative alopecia - A manikin study

BACKGROUND

Postoperative alopecia is a rare complication after surgery. The etiology is thought to be pressure-induced hair follicles ischemia caused by prolonged immobilized head. Headrest is always used as head positioner during operation. The contact pressure between the head and headrest is believed to be related to the development of postoperative alopecia. The aim of this study was to find a headrest with the minimum contact pressure.

METHODS

Five different materials headrests - folded sheet, foam donut, gel donut, natural latex, and memory foam were examined. The contact pressures between the manikin's head and tested headrests were continuously recorded for 4 h using CONFORMat System sensor. The average and peak pressures over the contact area were measured at 15 min, 30 min, 45 min, 1 h, 2 h, 3 h, and 4 h. A generalized estimating equations (GEEs) analysis and one way repeated measures ANOVA were used to assess the data.

RESULTS

The memory foam headrest showed the lowest average and peak contact pressures over the contact area (p < 0.05), and the natural latex headrest, gel donut headrest, foam donut headrest, and folded sheet headrest revealed increase of the contact pressures in order. The peak contact pressure of the gel donut headrest at 4 h was significantly higher than that of at 15 min (p = 0.032) and 30 min (p = 0.037).

CONCLUSION

Of the five headrests we examined, the memory foam headrest is suggested to be the best choice for surgical patients because of its lowest contact pressure.

Pressure-Induced Alopecia: Presence of Thin Hairs as a Trichoscopic Clue for the Diagnosis

Pressure-induced alopecia (PA) is an unusual pattern of circumscribed hair loss that occurs after ischemic changes on the scalp. Trichoscopic findings described in the literature are scarce, nonspecific, and include black dots, broken hairs, circle hairs, and erythema. However, we report 3 cases of PA in which trichoscopy also showed many vellus and thin hairs. Possibly, the maintenance of these hair shafts may be explained by the more superficial insertion of their bulbs on the skin and/or their lower metabolic rates, making them suffer less from local hypoxia. Therefore, the authors suggest that these relevant signs should be added as a clue for the diagnosis of PA in doubtful cases.

Headgear-induced temporary pressure alopecia

The development of hair loss associated with headgear use is a rare phenomenon. Pressure alopecia is a condition characterised by localised, non-scarring hair loss attributed to a mechanical cause. Factors such as prolonged periods of peri- and postoperative immobility have been implicated, as well as immunological and genetic predisposing factors. If the mechanical trauma is very prolonged, there is a risk of permanent follicle damage due to tissue hypoxia. A 13-year-old boy wore high-pull headgear as part of his orthodontic management. Within four weeks of headgear wear, localised areas of hair loss were seen corresponding with the areas of contact with the force delivery modules of the headgear. The patient experienced bullying at school as a result of this hair loss. Hair regrowth resumed after headgear use was discontinued, therefore confirming the diagnosis of temporary pressure alopecia. Temporary pressure alopecia is a rare side effect of orthodontic headgear. Alopecia can negatively impact an individual's psychosocial wellbeing; therefore, caution should be taken to avoid prolonged or excessive pressure in susceptible individuals and headgear patients should be regularly monitored.