Livedo reticularis associated with interferon alpha therapy in two melanoma patients

Livedo reticularis: a side effect of interferon therapy in a pediatric patient with melanoma

Livedo reticularis is a lacy mottling of the skin that can have many etiologies. We report a case of an 8-year-old boy with a diagnosis of melanoma who developed persistent livedo reticularis during treatment with interferon alpha-2B. To our knowledge, this is the first case report of livedo reticularis occurring as a side effect of interferon treatment for pediatric melanoma. Given the increasing incidence of pediatric melanoma, it is important that dermatologists be aware of potential side effects of interferon therapy to optimize care and education for these patients.

Livedo reticularis and related disorders

OPINION STATEMENT

Livedo reticularis is a violaceous mottling of the skin with a "fishnet" reticular appearance. Primary and secondary etiologies exist, including a pathologic variant termed livedo racemosa. No evidence-based medicine exists to guide therapy for this disorder, but most patients with primary and secondary livedo reticularis are asymptomatic and do not require treatment. In the rare instance that a patient with primary livedo reticularis experiences mild symptoms such as episodic numbness and tingling, avoidance of cold and vasoconstricting substances should be encouraged. Lastly, judicious dosing of a vasodilator such as a calcium channel blocker can be prescribed. Patients with secondary livedo reticularis or livedo racemosa may benefit from these same therapeutic suggestions; however, treating the proximate cause of livedo with a systemic association is encouraged and is most likely to yield cutaneous improvement. Although antiplatelet and/or anticoagulant therapy is often required when treating a patient with the antiphospholipid antibody syndrome or Sneddon's syndrome, the attendant livedo racemosa typically remains unchanged or progresses despite this treatment.

A review of adverse cutaneous drug reactions resulting from the use of interferon and ribavirin

Drug-induced cutaneous eruptions are named among the most common side effects of many medications. Thus, cutaneous drug eruptions are a common cause of morbidity and mortality, especially in hospital settings. The present article reviews different presentations of drug-induced cutaneous eruptions, with a focus on eruptions reported secondary to the use of interferon and ribavirin. Presentations include injection site reactions, psoriasis, eczematous drug reactions, alopecia, sarcoidosis, lupus, fixed drug eruptions, pigmentary changes and lichenoid eruptions. Also reviewed are findings regarding life-threatening systemic drug reactions.

[Livedo: from pathophysiology to diagnosis]

PURPOSE

We propose a diagnostic approach when facing a livedo. First, the pathophysiology of the livedo is reviewed using key articles barely quoted in the literature. Then the topic is handled in two ways. Figures and tables allow a rapid reading convenient "at the patient's bedside". The subject is also reviewed thoroughly, and we emphasize the intricacy of the various pathophysiological mechanisms involved for each livedo's related disease. Diseases associated with livedo are then briefly described with emphasis on the key diagnostic features and prevalence. Usefulness of the main diagnostic procedures is discussed.

CURRENT KNOWLEDGE AND KEY POINTS

A livedo is a usually purplish-blue erythema, reticulated (small and complete meshes) or racemosa (large broken circular segments) which is related to a slowdown of the blood flow in the dermic venules. These venules form adjacent circles communicating with each other, parallel to the skin surface. The blood flow slowdown may be due to a local vasoconstriction (vasomotor livedo) or to an arteriolar occlusion. Arteriolar occlusion may be related to blood abnormalities (thrombosis, high viscosity, embolus) or to increased parietal thickness (vasculitis, calcic deposition, intimal hyperplasia). It is not always possible to clinically distinguish a vasomotor livedo from those associated with diseases. Diagnostic procedures should be oriented by the medical history, the features of the livedo, and associated symptoms. Usefulness of the skin biopsy is usually limited to the situations where the livedo is infiltrated or necrotic.

FUTURE PROSPECTS AND PROJECTS

To raise controversy about their importance and implications, some pathophysiological data are presented: intimal pseudohyperplasia in Sneddon's syndrome and antiphospholipid syndrome, and white cell activation in essential thrombocythemia.