Proopiomelanocortin (POMC) and psychodermatology

Abstract

Psychodermatology is the crossover discipline between Dermatology and Clinical Psychology and/or Psychiatry. It encompasses both Psychiatric diseases that present with cutaneous manifestations (such as delusional infestation) or more commonly, the psychiatric or psychological problems associated with skin disease, such as depression associated with psoriasis. These problems may be the result either of imbalance in or be the consequence of alteration in the homoeostatic endocrine mechanisms found in the systemic hypothalamic‐pituitary‐adrenal axis or in the local cutaneous corticotrophin‐releasing factor‐proopiomelanocortin‐corticosteroid axis. Alteration in either of these systems can lead to immune disruption and worsening of immune dermatoses and vice‐versa. These include diseases such as psoriasis, atopic eczema, acne, alopecia areata, vitiligo and melasma, all of which are known to be linked to stress. Similarly, stress and illnesses such as depression are linked with many immunodermatoses and may reflect alterations in the body's central and peripheral neuroendocrine stress pathways. It is important to consider issues pertaining to skin of colour, particularly with pigmentary disorders.

Role of neurogenic inflammation in the pathogenesis of alopecia areata

“…29 When the body encounters different internal and external stimuli, such as stress, it activates the HPA pathway, which leads to the release of CRH in the paraventricular nucleus. 30 In the pituitary gland, the binding of CRH to receptors triggers the synthesis and release of pro-opiomelanocortin (POMC)-derived peptides. These include adrenocorticotropic hormone (ACTH), MSH, and β-endorphins.…”

The Hormonal Background of Hair Loss in Non-Scarring Alopecias

“…Evidence shows that stress can induce hair loss by acting through stress hormones [ 73 , 74 , 75 , 76 , 77 ]. Corticotropin-releasing factor (CRF), adrenocorticotropic hormone (ACTH), and cortisol belong to the main stress hormones in humans and constitute the elements of the hypothalamic–pituitary–adrenal axis [ 78 ].…”

“…The autoimmune pathway dominates and is based on the collapse in the immune privilege of HFs. HFs begin to show a higher expression of major histocompatibility (MHC) class antigens and become a target for the immune system [ 76 , 79 , 82 ]. Some studies in vitro suggest a restoration of the immune privilege of HFs in the treatment of AA.…”

“…The effect depends on the interruption of excessive CRH stimulation and the normalization of the HPA axis [ 84 ]. This field requires further studies [ 76 ].…”

“…Moreover, in the HFs incubated with CRH, the expression of anagen-promoting insulin-like growth factor-1 (IGF-1) and matrix keratinocyte proliferation was significantly lower than in controls. Interestingly, the effects mentioned above were blocked by caffeine [ 76 , 85 ].…”