Necrolytic acral erythema =الحمامى النخرية الانحلالية على النهايات |
Necrolytic acral erythema
Necrolytic acral erythema (NAE) was first described in 1996 by physicians in Egypt, M. El Darouti and M. Abu El Ela.1 Reports have continued to link hepatitis C with NAE.2 Necrolytic acral erythema manifests as well-circumscribed, dusky erythematous plaques with adherent scale. While the plaques are psoriasiform, they do not manifest an Auspitz sign as would be seen with psoriasis. Patients with active necrolytic acral erythema report burning or pruritus. It is limited to an acral distribution and, in most cases, is associated with hepatitis C infection.3,4 Several cases of necrolytic acral erythema have occurred in patients without hepatitis C.5 This suggests that necrolytic acral erythema might be a result of zinc dysregulation, rather than a result of hepatitis C infection itself. PathophysiologyThe pathophysiology of this condition is uncertain. Proposed theories for the cause of necrolytic acral erythema describe alterations in some metabolic factor, many of which are seen in other necrolytic erythemas, including necrolytic migratory erythema, pellagra, essential fatty acid and biotin deficiency, and acrodermatitis enteropathica. The hypothesized causes for the metabolic alteration include hypoalbuminemia, hypoaminoacidemia, low zinc level, increased glucagon, liver dysfunction, or diabetes. Only hepatitis C is universally present in all persons with necrolytic acral erythema.
HistoryPatients with necrolytic acral erythema present with a 1-month to 2-year history of a rash on the dorsum of the feet, which may or may not also involve the hands. In many cases, it has been unresponsive to topical steroids. Patients do not necessarily give a history of hepatitis C. Necrolytic acral erythema may be the presenting sign. Patients may report a burning sensation, especially when walking or standing. Sometimes, necrolytic acral erythema lesions are pruritic. The most common area of origination of the rash is the dorsal aspect of the great toe. It also occurs on the shins. In 43 of 44 reported cases, necrolytic acral erythema did not affect the palms or soles, the nail bed, nail plate, or mucous membranes. Williams8 reported a case of necrolytic acral erythema in an adolescent boy with a history of infection with hepatitis C virus; he had hepatic fibrosis, hypertension, and thrombocytopenia. The patient developed a pruritic eruption on his face, trunk, genitals, and extremities, and the eruption had a predilection for bony prominences. This patient did not respond to topical steroids, antihistamines, topical barrier repair creams, narrow-band UV-B therapy, or tar baths. A skin biopsy specimen demonstrated a nonspecific psoriasiform dermatitis consistent with necrolytic acral erythema. Hepatitis C virus RNA polymerase chain reaction studies showed 974,000 IU/mL (<50) and hepatitis C virus RNA genotype 1b. Janjua9 noted a 45-year-old man who developed well-defined erythematous hyperpigmented keratotic pruritic plaques on the dorsa of his feet and the lateral aspect of his ankles; he was determined to have necrolytic acral erythema. PhysicalDusky, red erythematous plaques are present bilaterally on the dorsum of the feet and toes. These may extend around to the skin overlying the Achilles tendon and up the lower leg, as depicted in the image below
The dorsum of the hands may or may not be involved. The lesions are clearly demarcated from uninvolved skin by a dark red border. The surface may be scaly, eroded, or velvety. Thick hyperkeratosis is sometimes present. Active lesions often include flaccid blisters. Edema may or may not be present. Abdallah et al10 describe stages of the lesions:
As a general rule, necrolytic acral erythema does not affect the palms or soles, the nail bed, nail plate, or mucous membranes. Hivnor et al11 reported a single case in which the plaques extended proximally to the thighs. This patient also had hyperkeratosis of the palms and soles and involvement of the face. While multiple biopsy specimens confirmed necrolytic acral erythema histologically, it is not clear whether these biopsy specimens were taken from the typical locations of necrolytic acral erythema or if the palms and soles were also included in the biopsy specimen. Other disorders that can be seen in persons with hepatitis C should be considered as possible epiphenomena. These include the following:
CausesThe cause is uncertain, but a metabolic alteration due to hepatocellular degeneration from hepatitis C infection is proposed. Many hypotheses describe deficiencies similar to those of the other necrolytic erythemas; histological features are similar among necrolytic acral erythema and other nutrient deficiencies. Note the following:
Laboratory StudiesHepatitis A, B, and C serologies: These are the most important tests because necrolytic acral erythema (NAE) has a high association with hepatitis C. Assess liver function, including aspartate aminotransferase, alanine aminotransferase, bilirubin, protein, albumin, and alkaline phosphatase values. Some authors believe the lesions are most active during the active stage of hepatitis. The severity of the lesions does not correlate with the severity of the hepatitis. Serum zinc, serum glucagon, and serum amino acid levels: These values have been reduced in some reported cases. Zinc deficiency associated with necrolytic acral erythema was noted by Najarian et al.13 Serum glucose and hemoglobin A1C levels: Consider performing these tests because necrolytic acral erythema may be more common in persons with diabetes and hepatitis C. Najarian et al has associated hypozincemia and hyperzincuria with necrolytic acral erythema.14 Imaging StudiesCT scanning of the liver and pancreas can be considered as an ancillary assessment. In some reported cases, the pancreas was imaged, most likely because some believe necrolytic acral erythema is a subset of necrolytic migratory erythema, a condition indicative of pancreatic glucagonoma. No pancreatic masses were found any of the patients imaged. ProceduresConsider skin biopsy to substantiate the diagnosis of necrolytic acral erythema. Consider liver biopsy to assess the status of hepatitis and before the institution of hepatitis C treatment. Histologic FindingsNecrolytic acral erythema is perhaps best defined clinically rather than histologically. Bentley et al noted a case of necrolytic acral erythema without classic histology findings, which responded to oral zinc therapy.15
El-Ghandour et al7 noted that electron microscope examination of patients with necrolytic acral erythema demonstrated clumped tonofilaments in the keratinocytes, yet hepatitis C virus RNA could not be detected in the plaques of necrolytic acral erythema.
Medical CareThe optimal treatment for necrolytic acral erythema (NAE) is the optimal treatment of hepatitis C—combination therapy with interferon and ribavirin. In one patient, ribavirin in addition to the interferon alfa therapy improved the necrolytic acral erythema despite the presence of a continued high viral load. Oral zinc replacement has been successful in some cases.4,16 Interferon alfa monotherapy has been reported to be effective treatment.4 Amino acid replacement therapy, both orally and parenterally, has yielded some improvement. Disease response to corticosteroid therapy (ie, topical, intralesional, and systemic) has been poor. No benefit has been seen with topical tar or tetracycline. El-Ghandour et al7 noted in their series of 23 Egyptian patients that interferon alfa combined with ribavirin caused regression of the plaques of necrolytic acral erythema in 3 patients and complete clearance in 1 patient. Oral zinc administration induced some improvement in the appearance of the skin in some patients. Surgical CareA surgical approach has not been shown to be therapeutically beneficial. ConsultationsConsultation with an infectious disease specialist, gastroenterologist, or hepatologist may be helpful for management of the hepatitis C. Consultation with a dermatologist may be helpful for diagnosis and management of cutaneous findings. DietSupplementation with zinc and amino acids has shown benefit. ActivityNo restrictions on activity are needed for persons with this condition. MedicationThe goal of treatment is to decrease the burning and pruritus and improve the appearance of the lesions of necrolytic acral erythema. Zinc sulfate,17 amino acid supplementation, and interferon alfa have been successful in treating necrolytic acral erythema. Topical tacrolimus has been reported as an effective treatment for necrolytic acral erythema.18 MineralsAct as enzyme cofactors and are required in metabolic processing. Zinc supplementsUse sulfate or gluconate zinc salt. Zinc sulfate 4.4 mg = 1 mg of elemental zinc. Zinc gluconate 7.1 mg = 1 mg of elemental zinc.
AdultEffective zinc sulfate dose used in studies: 440 mg PO qd (single dose or divided) for 100 mg/d of elemental zinc PediatricGeneral supplementation: 1-2 mg/kg/d elemental zinc; dose not documented in 12-year-old treated with zinc
May reduce penicillamine and tetracycline effects
Documented hypersensitivity
PregnancyC - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus PrecautionsCaution in patients with renal impairment InterferonsNaturally occurring compounds that have both antiviral and immunomodulatory effects. Peginterferon alfa-2a (Pegasys)Used in combination with ribavirin to treat patients with chronic hepatitis C who have compensated liver disease and have not previously received interferon alfa. Consists of interferon alfa-2a attached to a 40-kd branched PEG molecule. Predominantly metabolized by the liver.
Adult180 mcg SC qwk PediatricNot established
Theophylline may increase toxicity by reducing clearance; cimetidine may increase antitumor effects; zidovudine and vinblastine may increase toxicity
Documented hypersensitivity; decompensated liver disease; significant preexisting psychiatric disease; ongoing or recent alcohol use; platelet count <70,000/µL
PregnancyC - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus PrecautionsInsomnia; mental dysfunction (eg, mood dysfunction, depression, psychosis, aggressive behavior, hallucinations, violent behavior, suicidal ideation, suicide attempt, suicide, homicidal ideation [rare]), even without previous history of psychiatric illness; flulike symptoms; rash and pruritus; anorexia; neutropenia; thrombocytopenia; thyroid dysfunction; retinal abnormalities Peginterferon alfa-2b (PEG Intron)Escherichia coli recombinant product. Used to treat chronic hepatitis C in patients not previously treated with interferon alfa who have compensated liver disease. Exerts cellular activities by binding to specific membrane receptors on cell surface, which, in turn, may suppress cell proliferation and may enhance phagocytic activity of macrophages. May also increase cytotoxicity of lymphocytes for target cells and inhibit virus replication in virus-infected cells.
AdultInject SC qwk for 1 y using weight-based dosing PediatricNot established
Concurrent administration with IL-2 may increase nephrotoxicity; theophylline, zidovudine, and vinblastine may increase toxicity; cimetidine may increase antitumor effects
Documented hypersensitivity; autoimmune hepatitis; pancreatitis; colitis
PregnancyC - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus PrecautionsConsidered to have abortifacient potential; reduce starting dose by 50% or discontinue if serious adverse reactions develop during course of treatment (may reinitiate treatment if adverse reaction abates or decreases in severity); fatal and nonfatal pancreatitis or ulcerative and hemorrhagic colitis reported; life-threatening or fatal neuropsychiatric events may occur; severe suppression of bone marrow function may occur, sometimes resulting in severe cytopenias; may cause, headache, flulike symptoms, or myelosuppressive, pulmonary, thyroid, cardiovascular, or infectious disorders Nucleoside AnalogsDrugs that interfere with the production of DNA and RNA. Ribavirin (Virazole)Antiviral nucleoside analog. Chemical name is D -ribofuranosyl-1H-1,2,4-triazole-3-carboxamide. Given alone, has little effect on the course of hepatitis C. When given with interferon, significantly augments rate of sustained virologic response.
Adult10.6 mg/kg PO qd or divided bid PediatricNot established . |