A case of truncal complex regional pain syndrome: literature review

Introduction and importance

Complex regional pain syndrome is a rare and chronic pain disorder characterized by an abnormal level of pain disproportionate to the initiating cause, often manifesting well after the triggering event.

Case presentation

The authors present a free past medical history 33-year-old female, employed as a nurse in an intensive care unit, presented with a 9-year history of diffuse back pain. Her symptoms initially emerged at the neck with muscle spasms and restricted neck mobility, eventually progressing along the spine. Notably, the pain became episodic and intensified over time, significantly impeding her daily activities. Analgesic (non-steroidal anti-inflammatory drugs) treatments proved ineffective, and a distinct feature emerged-a change in skin colour to dark purple spots on her back, accompanied by hyperhidrosis and extreme tenderness. Despite an exhaustive evaluation involving bloodwork, inflammatory markers, serological tests, and radiographic imaging, a definitive diagnosis remained elusive until she responded positively to Pregabilin.

Clinical discussion

Although typically associated with extremities, this case challenges the conventional understanding of complex regional pain syndrome by showcasing its manifestation in the truncal region. The patient's clinical history, examination findings, and diagnostic journey are detailed herein, shedding light on the complexity and diagnostic considerations associated with this condition.

Conclusion

The case underscores the importance of a comprehensive approach and prompts a reevaluation of the existing guidelines to encompass such atypical presentations.

Klipple-Trenaunay Syndrome: A Rare Disorder With Multisystemic Clinical Attributes

Klippel-Trenaunay syndrome (KTS) is a rare disorder characterized by abnormal development of soft tissues, lymphatic system, and blood vessels. Major features include tissue and bone overgrowth, vein malformation, and port-wine stains with or without lymphatic abnormalities. It is crucial to review this rare syndrome to avoid any diagnostic delay. In addition, it is also vital to follow disease courses with symptomatic treatment for rare complex diseases, which would help clinicians understand and implement a better treatment plan in the future. We present the case of a 19-year-old male eventually diagnosed with KTS who initially presented with swelling of his feet and skin erosion with bloody discharge. Associated findings were bluish skin discoloration, nodularity, and bleeding per rectum, leading to anemia and subsequent heart failure. Colonoscopy/sigmoidoscopy showed vascular malformation and an active bleeding site. Our patient manifested most of the clinical attributes of KTS, with an interesting clinical course of arteriovenous, soft tissue, capillary, lymphatic, and vascular malformations. However, in our case, the patient is receiving only symptomatic treatment (blood transfusion) without any limb amputation or reconstruction surgery, leading to no further deterioration of the quality of life.

Argyria, an Unexpected Case of Skin Discoloration From Colloidal Silver Salt Ingestion

BACKGROUND

Argyria is a rare condition characterized by gray/blue dislocation of the skin caused by chronic exposure to silver salts.

CASE REPORT

We review the case of an 81-year-old man who presented to the emergency department after a motor vehicle accident, was incidentally found to have skin discoloration, and was ultimately diagnosed with argyria. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although most emergency physicians will not complete a toxicology fellowship, all emergency physicians are on the front line of toxicological presentations and should be able to recognize argyria and differentiate this condition from other causes of skin discoloration.

Ochronosis Presenting as Methemoglobinemia

Ochronosis is the blue-gray discoloration of collagen-containing tissues due to homogentisic acid (HGA) deposition, secondary to endogenous alkaptonuria or exogenous enzyme inhibition. In renal disease, accumulation of HGA in serum can cause methemoglobinemia. A 60-year-old woman with renal disease and anemia presented with 3 days of weakness and months of gray skin discoloration. Her hemoglobin was 8.1g/dl with 24.5% methemoglobin. Despite treatment with methylene blue, exchange transfusion, and continuous renal replacement therapy, the patient died. Autopsy revealed gray discoloration and ochronotic pigment in the ribs and cartilage. Based on these findings, the patient was diagnosed with ochronosis, suggestive of alkaptonuria, complicated by methemoglobinemia. The differential diagnosis for blue-gray skin discoloration includes argyria, methemoglobinemia, and ochronosis. This patient's clinical and autopsy findings suggested alkaptonuria complicated by methemoglobinemia due to progressive renal dysfunction. Development of methemoglobinemia in the setting of chronic skin discoloration and renal failure should prompt consideration of alkaptonuria.

Chemical Leukoderma Associated with Methylphenidate Transdermal System: Data From the US Food and Drug Administration Adverse Event Reporting System

OBJECTIVE

To identify and characterize cases of chemical leukoderma, an underrecognized adverse event, associated with the methylphenidate transdermal system (MTS) reported to the US Food and Drug Administration Adverse Event Reporting System (FAERS).

STUDY DESIGN

We searched the Food and Drug Administration Adverse Event Reporting System for reports of chemical leukoderma associated with MTS, received by the Food and Drug Administration from April 6, 2006 to December 23, 2014.

RESULTS

We identified 51 cases of chemical leukoderma reported with the use of MTS. The median age was 11 years; 43 cases reported leukoderma at or near the application site only, and 7 reported leukoderma at other parts of the body in addition to the application site; 1 case did not provide enough information to confirm the affected site. The time to onset ranged from 2 months to 4 years after the initiation of MTS. MTS was discontinued in 31 cases. Thirteen patients were prescribed treatment for repigmentation. Three cases reported continued spread of leukoderma after MTS was discontinued. Nineteen cases were diagnosed as vitiligo, including 5 cases reporting histologic features consistent with vitiligo. Leukoderma was persistent in all cases. The median follow-up interval after the discontinuation of MTS in 23 cases was 14 months.

CONCLUSIONS

As outlined in recent changes to the prescribing information for MTS, health care professionals need to be aware of the potential risk of chemical leukoderma caused by MTS, especially given that chemical leukoderma is often misdiagnosed as idiopathic vitiligo. MTS should be discontinued at the earliest sign of pigment loss and other treatment options considered.

Complex regional pain syndrome: medical and legal ramifications of clinical variability and experience and perspective of a practicing clinician

Objective

The aim of this study was to demonstrate the ramifications of clinical variability of complex regional pain syndrome (CRPS) and how they can affect the various aspects of this condition, favorably or unfavorably, for both patients and participating medical and legal professionals.

Methods

Twelve patients diagnosed with CRPS at different times in the past 25 years were followed up, and their signs and symptoms were reviewed for variability. None had preexisting or ongoing medical disorders and prior injury to the peripheral nerves or musculoskeletal tissues. None had been involved in litigation. Physical traumas that triggered CRPS were job-related, vehicular accidents, and personal injuries. The presence of vasomotor symptoms (eg, swelling, skin discoloration, and temperature changes) and allodynia in the affected extremity was the basis for clinical diagnosis in all the patients. The need for imaging studies was precluded in some patients owing to the presence of vasomotor symptoms, which either fluctuated or were steady. Seven of the patients had type 1 CRPS, and five patients had type 2 CRPS.

Results

Most patients encountered delay in diagnosis and treatment and legal obstacles owing to the lack of “typical” objective signs of CRPS. The patients’ symptoms fluctuated at different times of the day. Eight patients experienced spread of vasomotor symptoms and varying degree of allodynia in the opposite extremity. One patient, who developed signs and symptoms of rheumatoid arthritis, 2 months after the injury, continued to have CRPS symptoms in the injured hand. Treatment modalities administered in all the patients were essentially ineffective. All the patients, except one, were unable to return to their original line of work, and their symptoms persisted regardless of the outcome of their legal claims.

Conclusion

It is likely that patients who continue to complain of pain and vasomotor symptoms followed by a physical injury have CRPS. The complex interaction between the peripheral, autonomic, and central nervous system in this condition makes it challenging to diagnose, treat, and prognosticate.

New antiepileptic medication linked to blue discoloration of the skin and eyes

Ezogabine is an antiepileptic medication approved in June 2011 by the US Food and Drug Administration (FDA) as an adjunctive treatment for partial seizures. Minimal drug interactions and a novel mechanism of action made ezogabine an appealing new treatment option. However, adverse effects reported during clinical trials and following drug approval have been alarming. A Risk Evaluation Mitigation Strategy (REMS) program has been established for urinary retention. A safety alert was published in April 2013 warning ezogabine may cause retinal pigment abnormalities and/or blue-gray discoloration, most notably on or near the lips, nail beds, sclera and conjunctiva with long-term use. In October 2013, the FDA announced a formal label change to ezogabine to include a black boxed warning emphasizing the previously reported warnings of eye and skin discoloration and permanent vision changes. Given the unknown nature of the pathophysiology, consequences and potential for reversibility of these effects, GlaxoSmithKline and the FDA have published recommendations for patients currently receiving ezogabine. Further data from published case reports and long-term safety trials in the future may lend additional insight into these concerning effects.

Semi-permanent skin staining associated with silver-coated wound dressing Acticoat

A 17-year-old male with burns to 8% of his total body surface area was treated for 10 days with Acticoat(®), a nanocrystalline silver dressing. The burns, which were on his back and shoulder, healed without infection. However, a skin discoloration in the wound area and the adjacent uninjured skin appeared in the first days of treatment. The staining remained visible even after the treatment had ended and disappeared approximately three years later. Despite the outstanding antimicrobial properties, possible side effects of silver nanocrystalline dressings should be kept in mind.

Synthesis and biological evaluation of novel 2-methoxypyridylamino-substituted riminophenazine derivatives as antituberculosis agents

Clofazimine, a member of the riminophenazine class, is one of the few antibiotics that are still active against multidrug-resistant Mycobacterium tuberculosis (M. tuberculosis). However, the clinical utility of this agent is limited by its undesirable physicochemical properties and skin pigmentation potential. With the goal of maintaining potent antituberculosis activity while improving physicochemical properties and lowering skin pigmentation potential, a series of novel riminophenazine derivatives containing a 2-methoxypyridylamino substituent at the C-2 position of the phenazine nucleus were designed and synthesized. These compounds were evaluated for antituberculosis activity against M. tuberculosis H37Rv and screened for cytotoxicity. Riminophenazines bearing a 3-halogen- or 3,4-dihalogen-substituted phenyl group at the N-5 position exhibited potent antituberculosis activity, with MICs ranging from 0.25~0.01 μg/mL. The 3,4-dihalogen- substituted compounds displayed low cytotoxicity, with IC50 values greater than 64 μg/mL. Among these riminophenazines, compound 15 exhibited equivalent in vivo efficacy against M. tuberculosis infection and reduced skin discoloration potential in an experimental mouse infection model as compared to clofazimine. Compound 15, as compared to clofazimine, also demonstrated improved physicochemical properties and pharmacokinetic profiles with a short half-life and less drug tissue accumulation. This compound is being evaluated as a potential drug candidate for the treatment of multidrug resistant tuberculosis.