Diffuse reticulate purpura in an 11-year-old girl with severe malnutrition – A case report

Dear Editor, Diffuse reticulate purpura (DRP) is a rare and specific type of purpura observed in patients with anorexia nervosa (AN).[1] Herein, we report the case of an 11-year-old girl who presented with a weight loss of 10 kg over the last 4 months after changing to a diet of boiled and steamed food and exercising rigorously, including walking 15,000 steps per day and yoga. Before these lifestyle changes, she weighed 38 kg. She began restricting food intake because of abdominal fullness and constipation. The patient reported no uncontrollable gorging or vomiting during the period of diet change. Her initial body mass index (BMI) was 16.23, then declined to 12.13. She visited a pediatric clinic with abdominal fullness, abdominal pain, and constipation. For the restriction of food intake, the psychiatric doctor was consulted. She did not have an intense fear of gaining weight and knew the seriousness of low body weight. On admission to the pediatric ward, the patient exhibited bradycardia (35 bpm), hypothermia (35.3°C), and hypotension (systolic blood pressure <90 mmHg). Physical examination revealed general weakness and reticulate purpuric patches on the chest, abdomen, back, and extremities, sparing bony prominences [Figure 1a-c]. Dermoscopy revealed a more apparent reticular pattern of purpuric patches [Figure 1d]. Incisional biopsy revealed atrophic epidermis, slight dermal fibrosis, and minimal-to-mild perivascular infiltrates [Figure 2a]. No leukocytoclasia was observed. Lipoatrophy was observed in part of the subcutis [Figure 2b]. Focal areas of red blood cell extravasation, hemolysis, and hemosiderin deposition were observed in the deep dermis after iron, GLUT1 [Figure 2c], and ameba stains [Figure 2d]. No microthrombi were observed upon CD61 immunostaining. Laboratory tests revealed hyponatremia, hypophosphatemia, hypercholesterolemia, decreased free T4 levels, and elevated thyroid-stimulating hormone levels. Weight gain and skin lesions rapidly improved after adequate nutrition and calories were supplied. After discharge, her BMI gradually returned to 16.33 2 months later. Most of the lesions had completely faded 2 weeks later, except for lanugo-like hairs on the chest and abdomen [Figure 1e and f].Figure 1: Clinical pictures showing the diffuse reticulate purpura on the (a) abdomen, (b) posterior thighs, lower legs, and (c) popliteal area sparing bony prominence. (d) Dermoscopy showed a more apparent reticular pattern of purpuric patches. (e) Purpura disappeared after adequate nutrition. (f) Lanugo-like hairs were noted on the abdomen under dermoscopy after recovery.Figure 2: Pathology of skin biopsy. (a) The scanning view showed atrophic epidermis and minimal perivascular infiltration. (b) Mild lipoatrophy was observed in the subcutis. (c) Focal red blood cell extravasation was observed for GLUT1 stain and (d) ameba stain. (Hematoxylin and eosin, a: ×40; b: ×40; GLUT1, c: ×200; ameba, d: ×400).DRP was first reported in 2003 in two patients with AN.[1] In a recent summary, all previously reported six patients have AN (age range from 11 to 17 years old), with a male predominance.[2-4] Five patients reported changing their lifestyle patterns to steamed food and performing strenuous exercises. However, our case did not meet the criteria of AN in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, indicating that severe malnutrition alone could induce DRP. DRP predominantly affects the trunk and proximal extremities, sparing bony prominences. Other cutaneous symptoms include nail and hair fragility and cold extremities. Hypertrichosis lanuginosa was also observed in this case. Systemic symptoms included pitting edema, hypotension, hypothermia, and bradycardia. Laboratory tests revealed elevated serum aspartate transaminase or alanine transaminase levels in three cases, lactate dehydrogenase in two cases, creatine kinase in two cases, anemia in two cases, and thrombocytopenia in one patient.[1-4] Levels of Vitamin B12 and folic acid levels were usually within normal limits.[1-3] Histopathology was done in five cases which showed erythrocyte extravasation without vascular damage,[1-3] similar to our patient. The pathogenesis of DRP remains unknown. Intrinsic factors might include protein and/or vitamin deficiency caused by malnutrition. Starvation-induced bone marrow atrophy can cause coagulation anomalies and thrombocytopenia. However, laboratory abnormalities in the coagulation profiles and thrombocytopenia are usually mild or absent.[1-3] Although Vitamin C or K deficiency may cause purpura, the level of Vitamin C or K is normal in previously reported cases.[2,3] A relationship between reduced cutaneous collagen content and AN has also been demonstrated.[5] Weakening of capillary and dermal structures related to malnutrition could be another plausible explanation. This might be aggravated by exercise that damaged the fragile capillaries and induced leakage of erythrocytes. Vigorous exercise may cause exercise-induced purpura owing to an increase in vascular pressure during strenuous activities.[6] Differential diagnoses for DRP include scurvy, vasculitis, vasculopathy, disseminated intravascular coagulation, and infection. For example, reticulate purpura has been reported as an initial presentation of antiphospholipid syndrome.[7] Serum workup – including complete blood count, coagulation profile, blood cultures, electrolytes, metabolic panel, and urine toxicology – along with pathological examination, is helpful for excluding alternative diagnoses.[8] In conclusion, DRP is a benign but specific condition that might occur in severe malnutrition in addition to AN. The purpura rapidly disappears with adequate nutrition. A careful differential diagnosis to exclude other causes of purpura is recommended. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent form. In the form, the legal guardian has given consent for images and other clinical information to be reported in the journal. The guardian understands that name and initials will not be published and due efforts will be made to conceal the identity, but anonymity cannot be guaranteed. Data availability statement The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request. Financial support and sponsorship Nil. Conflicts of interest Dr. Yu-Hung Wu, an editorial board member at Dermatologica Sinica, had no role in the peer review process of or decision to publish this article. All authors declared no conflicts of interest in writing this paper.