Regression of BCC following immunosuppression withdrawal in a renal transplant recipient

the affected limb. Increased hair and nail growth appears several days after the onset of symptoms. In chronic stages, the skin turns bluish and becomes cold, with reduced hair and nail growth and atrophy of the skin. Early diagnosis and treatment including physical therapy and sympathetic blockade are essential, because CRPS in chronic stages is highly refractory to therapies. As the most prominent clinical finding of this case was unilateral linear skin atrophy, our first differential diagnoses included linear morphoea and atrophoderma of Pasini– Pierini. However, histopathological findings were not consistent with either disease. Progressive facial hemiatrophy (PFH) shares some common clinical and histological features with chronic stage CRPS, although the affected site differs. PFH has unilateral atrophy of the skin and subcutaneous tissue without sclerosis, and sometimes presents with neurological symptoms such as migraine headache and trigeminal pain. In addition, some reports state malfunction of sympathetic nerve system as a primary cause of the disease. The major mechanisms for CRPS are argued to be trauma-related cytokine release, exaggerated inflammation and sympathetically maintained pain. Sympathetic vasoconstrictor activity has been shown to be responsible for the pain and hyperalgesia. However, the mechanisms producing various skin changes are not fully elucidated. The atrophic changes seen in our case may also be the consequence of increased vasoconstrictor activity and the resulting decreased blood flow. It is possible to speculate that this unique linear arrangement reflects a cutaneous innervation pattern of affected sympathetic nerves. Further studies regarding the roles of the nervous system in the skin may shed light on the pathogenesis of the complex and diverse skin symptoms in CRPS.