This can occur during pregnancy, obesity, cold adaptation, stay in high altitudes, endurance exercise, acute psychosis, and post-traumatic stress disorder.According to newer theories, elevated concentrations of TSH and thyroid hormones in type 2 allostasis result from an up-regulated set point of the feedback loop, which ensues from increased TRH expression in the basolateral amygdala and the paraventricular nucleus of the hypothalamus in response to stress.High-T3 syndrome in thyroid carcinoma may result from autonomous thyroid hormone secretion or overexpression of type 2 deiodinase in cancer cells rather than from type 2 allostasis. Conditions with mixed phenotypes
Psychiatry
Stress suppresses TSH, and alterations in thyroid hormone levels may arise  in psychiatric illness. In major depressive disorder, an NTIS-like phenotype may be observed, with reduced T3 and increased rT3. T4 may be elevated, and TSH is usually normal, although TSHs normal circadian rhythm may be disrupted. Bipolar 1 and PTSD can exemplify an anti-NTIS phenotype, with upregulation of the HPT axis and increased T3. This may also occur during acute schizophrenic episodes. Exercise
After exercise, a transient increase occurs in TSH, T4, and T3, but this is thought to be due to increased blood concentration as a result of dehydration. The effects normalize after rest. After long-term heavy strain, levels of thyroid hormones decrease. This is exacerbated by other stressors such as undernutrition and lack of sleep, such as in a military training setting. During endurance exercise, before exhaustion, elevated thyroid hormone levels may happen due to increased expected energy demand (type 2 allostatic load).
Eruptive vellus hair cysts (or EVHC) are small lesions that occur most often in the chest wall, abdomen and extremities, often with a crusted surface. : 680  EVHC may occur randomly, or it can be inherited as an autosomal dominant trait. The condition affects males and females equally, and sporadic cases usually appear at 4–18 years of age. The cysts appear similar clinically to steatocystoma multiplex, as well as acneiform eruptions and milia. Therapeutic techniques that are safe and effective are rare, with incision and drainage being the primary form of treatment when sporadic regression does not occur. It was first described in 1977. Signs/symptoms
Cause
Diagnosis
Histopathology is the basis of diagnosis. Stratified-squamous epithelium with a granular layer that surrounding a cystic space filled with laminated keratin and a variable number of vellus hair cysts is seen to be present. It can be difficult to distinguish from other skin conditions, including molluscum contagiosum and acne vulgaris but can be corroborated with histopathology. Associations
It can be associated with Steatocystoma multiplex. Treatment
The primary indication for treatment is cosmesis. Retinoids, surgery, and lasers are used as treatment modalities. See also
Steatocystoma simplex
Milia
List of cutaneous conditions

References
Further reading
Torchia, Daniele; Vega, Janelle; Schachner, Lawrence A. (1 February 2012). "Eruptive Vellus Hair Cysts". American Journal of Clinical Dermatology. 13 (1): 19–28. doi:10.2165/11589050-000000000-00000. PMID 21958358.