The human race is exposed to vagaries of life in terms of various hazards; or as the
Greek would have it, “we are all but a heartbeat away from disaster.” Major cause
for psychopathology has been attributed to stress. A catalyst or precipitator of psychiatric
illness and a stimulant to substantial mental agony. The term “stress” was coined
by Hans Selye (1907-1982) who laid the concept of the adrenocortical system being
the vital responder to stress.[1] The more rudimentary term psychosomatic disease
mirrors those illnesses whose evolutions are channeled by psychological (thoughts,
emotions and behavior) issues; in contrast somatopsychic diseases echoes those where
the biologic aspect of the disease affects the psyche.[2] Psychocutaneous medicine
impacts on the interaction between the mind, the brain and the skin. The brain and
the skin originate from same germ layer i.e., the embryonic ectoderm and are under
the influence of the same hormones and neurotransmitters. Psychiatric expertise focuses
on the “internal indiscernible disease” conversely dermatological expertise focuses
on “external discernible disease.” Factors of a psychopathological nature tend to
play an etiological role in the development of skin disorders, can exacerbate pre-existing
skin disorder as well as patients suffering from dermatological disorders may bear
the brunt of disfigurement.[3] Psoriasis being a key disease in the cluster of psychocutaneous
disorders, it has become a focus for exploration. Due to the intimate interplay between
psychosocial factors and psoriasis, this disease confirms the said definitions.[2]
Psoriasis is a common, chronic, recurrent inflammatory disease of the skin, characterized
by circumscribed, erythematous, dry, scaly plaques of varying sizes.[2] The incidence
of disease is 1-2% of the general population.[4
5] Stress acts as a catalyst for the onset as well as exacerbation of psoriasis.[6
7
8] The neurogenic inflammation hypothesis of psoriasis put forth by Farber et al.
states that neuropeptides like substance P (SP) and nerve growth factor (NGF) act
as a crux in its pathogenesis. Unmyelinated terminals of sensory fibers in skin release
SP and other NP's thereby resulting in generation of local neurogenic inflammation
in those who are genetically primed.[1] SP is synthesized in the dorsal root ganglion
of nociceptor C fibers and transmitted peripherally in granules. Colocalization with
other NP's including calcitonin gene related peptide and vasoactive intestinal peptide
(VIP) in cutaneous sensory nerve endings are found via histochemical staining methods.[9]
Stressful life events are associated with higher levels of SP in the central and the
peripheral nervous system of animal models.[1] SP expressing neurons are in close
and functional proximity of mast cells, which when activated release VIP.[10] Autonomic
pathways of the descending type via dorsal root ganglia in the spinal cord through
SP containing neurons stimulate release of NP's, the neurons extend onto having connections
to opioid interneurons in the dorsal horn. Increased release of adrenocorticotropic
hormone, glucocorticoids and adrenalin during stress may be attributed to the stimulation
of hypothalamic-pituitary-adrenal axis. Significantly increased expression of NGF
in keratinocytes regulates skin innervations and up regulates NP's, this has found
to be an early event in the pathogenesis of Psoriasis. NGF causes the proliferation
of T lymphocytes and brings about mass cell degranulation resulting in production
of a chemokine resulting in production of a chemokine RANTES,which is chemotactic
for resting Cd4+ memory t cells and memory t cells.[1]
The severity of psoriasis is found to be ever fluctuating. Individuals are likely
to cycle between differing levels of severity throughout their life time. The course
of the disease is punctuated by spontaneous flare-ups and remissions.[11] Study done
on 141 individuals from 2 settings: An outpatient skin clinic at King's College Hospital
and the Psoriasis Association demonstrated that around 60% of those with psoriasis
believe that stress/psychological factors are causal. Findings confirmed that causal
attributions are associated with the psychological impact of psoriasis i.e., people
with psoriasis who believe the cause of their psoriasis to be emotional were more
likely to experience pathological worry than those who believed cause to be physical.
However, perceived stress was not related to psoriasis severity. A level of perceived
stress was found to be related to quality of life, depression and anxiety. Findings
suggested that stress is not associated to an increase in symptoms, but an increase
in the impact the symptoms have on daily life and well-being.[11]
Case-control study conducted on a large population has demonstrated an independent
link between stress related disorders and psoriasis.[12] Studies report high rates
of stressful incidents having occurred before the onset of psoriasis flares approximately
in 68% of adult patients, although they were of uncontrolled nature. In addition,
retrospective data have demonstrated that patients with psoriasis report more frequent
traumatic experiences in childhood and through adulthood.[13] Both stress and worry
were found to be factors that impede clearance of psoriatic lesions in patients being
treated with significantly different treatment and placebo arms.[14]
An unhealthy diet and sedentary life-style are quite common in patients with psoriasis
than those without.[14] Psoriasis being a chronic and often disfiguring condition,
those with it also suffer a marked impairment in quality of life.[15] In contrast
to other chronic diseases like heart failure or cancer, psoriasis does not pose to
be a life threat despite which its impact is magnanimous.[16] Preoccupation about
people's perception of them and avoiding physical contact with others in order to
prevent social rejection and shame are beliefs reported by several qualitative studies.[17]
Due to the constant skin shedding and exorbitant time consuming treatments aimed at
achieving remission, patients may view their lesions as stigmata leading to evolution
of guilty feelings with their disease process.[18] Although the potential contributors
of depression in psoriasis are numerous, they mostly evolve from poor quality of life
and may include increased rates of pruritus, social stigmatization, joint manifestation
and poor treatment compliance all of which have been associated with depression in
previous studies.[19] Sharma et al. found that depression occurred more frequently
and that sleep interference was the most common psychiatric symptom. Likely sources
of sleep impairment are pruritus, low mood, pain and breathing difficulty. Furthermore,
SP is found to play a role in sleep impairment, also proposed in the pathogenesis
of psoriasis and may be linked to the relation between psoriasis, depression and sleep
quality.[20
21]
The National Psoriasis Foundation, USA states that in addition to the physical impact,
psoriasis significantly affects mental and emotional functioning. Psoriasis is independently
associated with depression, psoriasis patients are twice as likely to have suicidal
thoughts compared with the general population and people with chronic illnesses. 10%
of surveyed patients expressed a wish to be dead. The association of psoriasis has
also been linked to stress related disorders and behavior disorders.[22] Reports state
that the subgroup of patients found to be “stress reactors” appear to have better
long-term prognosis and course of disease may be altered by early incorporation of
psychosocial interventions.[5] The social and emotional impacts of the disease is
greatest among women, young people and minorities.[21]
People with psoriasis report feeling self-conscious, embarrassed and helpless. The
physical pain and seriousness of disease, as well as its adverse emotional effects
are frequently undermined by others and can lead to a vicious cycle of despair for
many with psoriasis. The social stigma associated with the disease state eventually
manifests as low self-esteem and contribute to poor psychosocial adjustment.[23] Coping
mechanisms such as avoiding being in public, indulging in over-eating and alcohol
abuse are often sought by the patients. It can attribute to/exacerbate other serious
co-morbid health conditions namely obesity, heart disease.[24
25
26] This cycle is continued when unaddressed mental health problems prevent patients
from effectively managing their disease. Inadequate treatment access can also lead
to depression and anxiety. These psycho-social impacts can therefore negatively affect
the progression of disease, as stress is a documented trigger for flares of both psoriasis
and psoriatic arthritis.[23]
Hence the adverse mental health aspects of psoriasis have multifaceted dimensions,
not only do they have a direct psychological bearing, but can also potentially worsen
the disease process, thereby amalgamating the psycho-social effects. As a result,
state of mental health can interfere with patients’ ability to adhere to and respond
to treatment. The burden of disease ranging from physical pain, psychological distress
and social ostracization further escalates it. Additionally, control of psoriasis
symptoms has been associated with improvement in psychological symptoms. Therefore
people with psoriasis must receive treatment encompassing primary, specialty and psychiatric
care. Lastly, development of quality measures, timely interventions and standards
of care related to holistically treating psoriasis patients would help improve care
delivery and patient well-being outcomes.