Diagnosing the Dermatologic Blues: Systematic Review of the Rare Conundrum, Psychogenic Purpura (Preprint)

Abstract

BACKGROUND Psychogenic purpura (PP) is an idiopathic psychodermatologic condition of recurrent, painful purpura precipitated by psychological stress predominantly affecting young females. Little consensus on the diagnostic guidelines for this rare condition exists, often resulting in costly, unnecessary, and stressful investigations as well as prolonged hospital admissions. OBJECTIVE With this first up-to-date systematic review of 134 cases of PP in over a decade, we aim to thoroughly investigate the diagnostic strategy and treatment regimens used in the last decade. With a prompter diagnosis, patient stress and nosocomial ecchymoses can be minimized and treatment can be expedited. METHODS A literature review of four databases (PubMed, OVID Embase, OVID Medline and Web of Science databases) yielded 46 full-text articles, which were reviewed and extracted by two independent reviewers. RESULTS We analyzed a total of 134 cases, consisting largely of females (N=125) with purpura on the upper (76.9%, N=103) or lower limbs (83.6%, N=112). Apart from a paresthesia prodrome, patients commonly experienced headache, malaise, and arthralgia or myalgia. 70.1% of patients (N=95) reported a physiological or psychological stressor or psychiatric diagnosis prior to the development of the purpura. Laboratory testing almost always revealed unremarkable results. The intradermal washed autoerythrocyte sensitization test was positive in 97.7% (N=42) of cases. Histopathology biopsy findings commonly revealed dermal erythrodiapedesis or hemorrhage (N=34) and perivascular inflammatory infiltrates (N=17). 41.8% of patients (N=56) received a novel psychiatric diagnosis, with depression being the most common (56%, N=40). In both patients with or without a novel psychiatric diagnosing, observation, counselling or support, treatment with antidepressants (i.e., SSRIs), and psychotherapy (i.e., cognitive behaviour therapy) prevailed in resolution of the purpura. CONCLUSIONS Due to the unclear etiology and infrequent presentation of this condition, it remains a diagnosis of exclusion based on clinical suspicion evaluating presence of stressors or psychiatric co-morbidities and exclusion of systemic conditions. Clinical confirmation can be sought through a positive autoerythrocyte sedimentation test, characteristic histopathology findings and remission of purpura following psychiatric treatment.