Acquired reactive perforating collagenosis triggered by insect bite

Acquired reactive perforating collagenosis triggered by trauma with eosinophilia: a case report and literature review

Acquired reactive perforating collagenosis (ARPC) is a rare dermatological disorder condition defined by the perforation of altered collagen fibers through the epidermis. The presence of underlying conditions such as diabetes or renal disease is helpful in the ARPC diagnosis. Although skin rashes related to ARPC have been reported, the exact causative factors and mechanisms remain unclear. Here, we present a unique case of ARPC triggered by trauma in a 67-year-old male without concurrent systemic alterations. The diagnosis of ARPC with eosinophilia was made following comprehensive diagnostic testing, including clinical presentation, histological results, and blood tests, ruling out other possible diseases. Intriguingly, the histopathological examination revealed collagen penetration into the epidermis at different tissue sections. In addition, we reviewed existing literature on ARPC, which documented the causation. To help confirm the diagnosis, clinicians have to pay attention to traumatic triggers for ARPC and its rare manifestation with eosinophilia.

Reactive Perforating Collagenosis; An Uncontrolled Pruritus That Left You Scratching Your Head

Acquired perforating collagenosis is a rare disease of altered collagen formation that is extruded through the epidermis. It is most commonly seen in patients with microvascular disease including longstanding diabetes and chronic kidney disease (CKD). Due to the rarity of the disease, no large randomized clinical studies have been performed to determine the most efficacious method of treatment. Therefore, most of the knowledge available for treatment is secondary to the information collected through case reports, case series, and retrospective analyses.

In this report, we present the case of a 68-year-old male with history of stage IV CKD who presented with a severe skin rash that was present over his body, including the chest, arms, back, neck, and buttocks. It did not involve the mouth, legs, palms or soles of the feet. He did not have a significant history of diabetes and had been placed on steroids with the concern that this rash may have been secondary to a drug reaction, erythema multiforme, or bullous pemphigoid. Two skin biopsies were performed as the patient was not responding to systemic and topical steroid or oral antibiotic therapy. The final biopsy ultimately revealed a diagnosis of acquired perforating collagenosis.

This is unusual in our case because although our patient had advanced CKD, he was not on dialysis, and had no significant longstanding history of diabetes. Additionally, as the prevalence of CKD is increasing in the population, it becomes more pertinent for providers to be aware of dermatological conditions associated with advanced CKD. This case report seeks to raise awareness of this disease. Furthermore, as the initial skin biopsy was unrevealing, this case also emphasizes the importance of repeating a biopsy to reduce the chance of sampling error.

Acquired reactive perforating dermatosis

Acquired reactive perforating dermatosis is characterized by umbilicated erythematous papules and plaques with firmly adherent crusts. Histopathological examination shows a typical cup-shaped ulceration in the epidermis containing cellular debris and collagen. There is transepidermal elimination of degenerated material with basophilic collagen bundles. The etiology and pathogenesis of acquired reactive perforating dermatosis are unclear. Metabolic disorders and malignancies are associated with this dermatosis. Associated pruritus is regarded as a key pathogenic factor. Constant scratching may cause a repetitive trauma to the skin. This pathogenesis may involve a genetic predisposition. The trauma may lead to degeneration of the collagen bundles. Treatment of acquired reactive perforating dermatosis follows a multimodal approach. Apart from the treating any underlying disease, treatment of pruritus is a major goal. Systemic steroids and retinoids, as well as UVB phototherapy are well-established treatment options. Some patients may also benefit from oral allopurinol.