Selective Cryolysis of Sebaceous Glands

Revisiting the Role of Local Cryotherapy for Acne Treatment: A Review and Update

Acne vulgaris is a well-recognized condition among adolescents and adults that adversely affects their quality of life. Local cryotherapy has long been reported to be effective in treating acne vulgaris, inducing a more rapid involution of acne than topical medications. However, the use of cryotherapy has been limited for acne treatment due to several drawbacks, including procedural pain and pigmentary alterations. Currently, newer cryotherapy devices are gaining attention in dermatology due to their ability to monitor and precisely control the target temperature. In this narrative review, a brief history and the latest update on acne cryotherapy will be presented. Additionally, a special emphasis is placed on the role of cryotherapy, alone or in combination with intralesional steroid injections for nodulocystic acne.

A Correlation between Serum Level of Alkaline Phosphatase and Acne Severity in Children and Adolescents: A Retrospective Cross-Sectional Study

Background

Acne is a chronic inflammatory disease of the pilosebaceous unit and usually affects adolescents when the peak concentrations of growth hormone, insulin-like growth factor 1, and androgen are demonstrated. The activity of alkaline phosphatase (ALP), which increases physiologically in growing children and adolescents, in the pilosebaceous unit has been reported. However, the correlation between the serum level of ALP and the number of acne lesions has not been studied.

Objective

The present cross-sectional study was designed to evaluate the correlation between serum level of ALP and the numbers of non-inflammatory and inflammatory acne lesions in children and adolescents.

Methods

For this study, 202 pediatric and adolescent patients clinically diagnosed with acne vulgaris were included. Age, sex, serum level of ALP, number of non-inflammatory acne lesions, number of inflammatory acne lesions, and number of total acne lesions were evaluated. Additionally, the serum level of dehydroepiandrosterone sulfate was evaluated in 117 patients. Multiple regression analysis was performed. Multicollinearity was quantified using the variance inflation factor.

Results

In the 202 patients, serum level of ALP was the only independent factor that significantly affected both the number of non-inflammatory acne lesions and of total acne lesions (regression coefficient=0.089 and 0.086, respectively, p<0.001).

Conclusion

There was a significant correlation between serum level of ALP and the extent of acne (non-inflammatory acne lesions and total acne lesions).

Neuroendocrinology and neurobiology of sebaceous glands

The nervous system communicates with peripheral tissues through nerve fibres and the systemic release of hypothalamic and pituitary neurohormones. Communication between the nervous system and the largest human organ, skin, has traditionally received little attention. In particular, the neuro-regulation of sebaceous glands (SGs), a major skin appendage, is rarely considered. Yet, it is clear that the SG is under stringent pituitary control, and forms a fascinating, clinically relevant peripheral target organ in which to study the neuroendocrine and neural regulation of epithelia. Sebum, the major secretory product of the SG, is composed of a complex mixture of lipids resulting from the holocrine secretion of specialised epithelial cells (sebocytes). It is indicative of a role of the neuroendocrine system in SG function that excess circulating levels of growth hormone, thyroxine or prolactin result in increased sebum production (seborrhoea). Conversely, growth hormone deficiency, hypothyroidism, and adrenal insufficiency result in reduced sebum production and dry skin. Furthermore, the androgen sensitivity of SGs appears to be under neuroendocrine control, as hypophysectomy (removal of the pituitary) renders SGs largely insensitive to stimulation by testosterone, which is crucial for maintaining SG homeostasis. However, several neurohormones, such as adrenocorticotropic hormone and α-melanocyte-stimulating hormone, can stimulate sebum production independently of either the testes or the adrenal glands, further underscoring the importance of neuroendocrine control in SG biology. Moreover, sebocytes synthesise several neurohormones and express their receptors, suggestive of the presence of neuro-autocrine mechanisms of sebocyte modulation. Aside from the neuroendocrine system, it is conceivable that secretion of neuropeptides and neurotransmitters from cutaneous nerve endings may also act on sebocytes or their progenitors, given that the skin is richly innervated. However, to date, the neural controls of SG development and function remain poorly investigated and incompletely understood. Botulinum toxin-mediated or facial paresis-associated reduction of human sebum secretion suggests that cutaneous nerve-derived substances modulate lipid and inflammatory cytokine synthesis by sebocytes, possibly implicating the nervous system in acne pathogenesis. Additionally, evidence suggests that cutaneous denervation in mice alters the expression of key regulators of SG homeostasis. In this review, we examine the current evidence regarding neuroendocrine and neurobiological regulation of human SG function in physiology and pathology. We further call attention to this line of research as an instructive model for probing and therapeutically manipulating the mechanistic links between the nervous system and mammalian skin.

Emerging Therapies for Acne Vulgaris

As we gain a greater understanding of acne pathogenesis, both new agents as well as new uses for established drugs are being considered for the treatment of acne vulgaris. Multiple clinical trials assessing new formulations or combinations of established acne treatments have been conducted, and novel uses of antimicrobials such as modified diallyl disulfide oxide and nitric oxide are being assessed in clinical trials. There are also a multitude of new therapies currently being studied that target the inflammatory cascade of acne pathogenesis, including sebosuppressive and anti-inflammatory phytochemicals, and  small molecule inhibitors targeting sebaceous glands and enzymes, among others. Laser and light therapy is also being modified for the treatment of acne through combination methods with metal nanoshells and vacuum assistance. Probiotics have gained popularity in medicine as greater knowledge of the microbiome and its effects on multiple organ systems is being elucidated. Studies describing the positive effects of certain ammonia-oxidizing bacterial strains in the regulation of the skin's inflammatory response are ongoing. Therapies for acne are constantly evolving and current gold-standard acne therapy may be supplemented with novel treatment modalities in the near future.

Seeking new acne treatment from natural products, devices and synthetic drug discovery

Despite lots of research on the pathogenesis of acne, the development of new therapeutic agents is still stagnant. Conventional agents which target multiple pathological processes have some serious side effects and this makes seeking new treatment options important for treating acne. As new therapeutic options, researchers are focusing on natural products, synthetic drugs and devices. From natural products, epigallocatechin-3 gallate, lupeol, cannabidiol and Lactobacillus fermented Chamaecyperis obtusa were reported to be possible candidates for novel drugs, targeting multiple pathogenic factors. Synthetic anti-P.acnes agent, nitric oxide nanoparticles and α-mangostin nanoparticles are shown to be effective in acne treatment. Device or procedural methods such as fractional microneedling radiofrequency, cryolysis, photothermolysis and daylight photodynamic therapy have potential as new treatment options for acne. Further large clinical trials comparing these new treatments with existing agents will be necessary in the future.

Evaluation of the Efficacy of Cryosurgery in Patients With Sebaceous Hyperplasia of the Face

Background:

Cryosurgery is an effective treatment for sebaceous hyperplasia, but there have been few clinical studies.

Objectives:

The aim of this study was to evaluate the efficacy and safety of cryosurgery in the treatment of sebaceous hyperplasia.

Methods:

Cryosurgery was performed 6 times, at 2-week intervals, with liquid nitrogen, and evaluated in 40 patients with 517 lesions ranging from 2 to 9 mm over the forehead, cheeks, and chin. All of the lesions were measured before and after the treatment.

Results:

The mean age of the participants was 54.7 ± 8.9 years, and the male/female ratio was 21/19 (1.1). The mean time of the disease duration was 4.2 ± 3.0 years. After 6 cooling cycles, an excellent response (76%-100%) was seen in 341 patients (65.9%), a very good response (51%-75%) was seen in 102 (19.7%), a good response (26%-50%) was seen in 57 (11.1%), a poor response (1%-25%) was seen in 15 (2.9%), and no response (0%) was seen in 2 (0.4%). Age ( P = .004) and sex ( P < .0001) were independent predictors of an excellent response. The excellent response rates were 71.4% for males, 61.8% for females, 70.4% for ages older than 55 years, and 61.8% for ages younger than 55 years. Temporary hyperpigmentation was found in 5 lesions (0.96%), and recurrence was not seen at the 4-month follow-up.

Conclusions:

The well-aimed and controlled used of cryosurgery is an effective method for treating significant cosmetic disfigurement in patients with sebaceous hyperplasia. It is a low-cost therapy without scarring, hypopigmentation, or recurrence.