A multicentre study to determine the value and safety of drug patch tests for the three main classes of severe cutaneous adverse drug reactions.

BACKGROUND: Drug patch tests (PTs) can reproduce delayed hypersensitivity to drugs and entail a moderate re-exposure of patients to offending drugs. OBJECTIVES: To determine the value of PTs for identifying the responsible drug in severe cutaneous adverse drug reactions (SCARs) such as acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) and Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). METHODS: In a multicentre study, PTs were conducted on patients referred for DRESS, AGEP or SJS/TEN within 1 year of their SCAR. All drugs administered in the 2 months prior to and the week following the onset of the SCAR were tested. RESULTS: Among the 134 patients included (48 male, 86 female; mean age 51·7 years), positive drug PTs were obtained for 24 different drugs. These included positive tests for 64% (46/72) of patients with DRESS, 58% (26/45) of those with AGEP and 24% (4/17) of those with SJS/TEN, with only one relapse of AGEP. The value of PTs depended on the type of drug and the type of SCAR (e.g. carbamazepine was positive in 11/13 DRESS cases but none of the five SJS/TEN cases). PTs were frequently positive for beta lactams (22 cases), pristinamycin (11 cases) and in DRESS with pump proton inhibitors (five cases), but were usually negative for allopurinol and salazopyrin. Of 18 patients with DRESS, eight had virus reactivation and positive PTs. In DRESS, multiple drug reactivity was frequent (18% of cases), with patients remaining sensitized many years later. CONCLUSIONS: PTs are useful and safe for identifying agents inducing SCAR.

[Proxy lymphomatoid contact dermatitis]. / Dermite de contact lymphomatoïde par procuration.

BACKGROUND: Lymphomatoid contact dermatitis is a delayed hypersensitivity reaction predominantly featuring T-cell infiltration. We report a case mainly involving B-cell infiltration associated with eczema and resulting from an indirect proxy contact with an allergen in a conjugal setting. PATIENTS AND METHODS: A 32-year-old man had an infiltrated cutaneous lesion on the interior aspect of the left arm with eczematous lesions of the waist and the anterior aspect of the left arm which were present for 6 months. All of these lesions were unresponsive to strong local steroids. Biopsy of the infiltrated lesion showed a dense lymphoid dermal infiltration chiefly comprising B cells. Histological examination of a waist lesion revealed chronic eczema. Patch testing was performed with the ECDRG test battery. A PPD (paraphenylenediamine) patch test was the only examination yielding a positive result. Detailed questioning revealed use of a hair dye by the patient's spouse and withdrawal of the allergen resulted in complete remission of the two types of lesion. DISCUSSION: This case highlights the ability of a single allergen to induce different lymphoid phenotypes. It also underscores the value of detailed questioning in allergology.

[Nodular thrombophlebitis and granulomatous systemic disease]. / Thrombophlébites nodulaires et maladies systémiques granulomateuses.

INTRODUCTION: Nodular thrombophlebitis is septal hypodermitis characterised by vasculitis with vein thrombosis. It may indicate serious underlying disorders. EXEGESIS: We present two cases of nodular superficial phlebitis, which revealed tuberculosis and sarcoidosis. CONCLUSION: Nodular thrombophlebitis are classic during evolution of Behçet disease or Buerger vasculitis. In sarcoidosis, erythema nodosum and granulomatous involvement are the most common cutaneous manifestation. Nodular thrombophlebitis has never been described. Panniculitis are classical in tuberculosis. But most cases are erythema nodosum and cases of erythema induratum of Bazin. Nodular thrombophlebitis could reveal thrombophilic abnormalities, and even more neoplasms especially when they are recurrent and migratory.

[Carcinoma cuniculatum: an uneasy diagnosis to suspect in case of chronic osteomyelitis with unsuccessful outcome despite appropriate antibiotic therapy]. / Carcinome cuniculatum: un diagnostic difficile, à évoquer devant une ostéite chronique d'évolution défavorable sous traitement.

INTRODUCTION: The clinical and histological features of cuniculatum carcinoma (CC) are often misleading. CASE REPORT: We report a case of CC of the foot, which was misdiagnosed as osteomyelitis for a two year period and which relapsed 2 months after complete resection. DISCUSSION: The CC has to be evoked in patients with chronic osteomyelitis and torpid wound. The anatomopathologist needs to be aware of the suspected diagnosis.

[Erosive pustular dermatosis of the leg: role of zinc deficiency?]. / Dermatose pustuleuse érosive des jambes: rôle de la carence en zinc?

BACKGROUND: Erosive pustular dermatosis of the legs is a rare and recently described condition seen in elderly subjects. It is characterised by symmetric erosions of the legs resulting from a confluence of sterile pustules, usually following minor trauma. Treatment with dermal corticosteroids is rapidly effective but is not codified and relapse is common. CASE-REPORTS: Three patients aged respectively 74, 84 and 92 years presented ulcers of the legs and ankles associated with peripheral pustules following minor injury. These pustules were sterile and exhibited a spongiform appearance on histological examination. None of these patients had a prior history of psoriasis. However, all presented zinc deficiency. Treatment with dermal corticosteroids combined with oral zinc gluconate resulted in complete resolution in two of the patients after several days of therapy and proved effective during relapse in the third patient. DISCUSSION: Erosive pustular dermatosis of the legs is a benign dermatosis that is probably under-reported that should be included in the category of inflammatory neutrophilic dermatoses. The cases we present suggest a triggering or enhancing role of zinc deficiency.

Generalized pustular psoriasis complicated by acute respiratory distress syndrome.

Psoriasis has a chronic and relatively benign course. However, severe complications are possible. One rare complication is acute interstitial pneumonitis. This entity should be suspected when a patient presents with dyspnoea and high fever. Knowledge of this pathology is crucial, for although it is essential to rule out aetiologies requiring specific management such as microbial infection or drug-related syndromes, diagnosis should not be delayed as its severe clinical course is improved by corticosteroids. We report two patients with an acute respiratory distress syndrome arising during the course of pustular psoriasis. Repeated bacteriological testing in lungs and blood remained negative. In both cases lung involvement was severe, requiring artificial ventilation. Dramatic clinical resolution was obtained by using corticosteroids. Besides infectious causes and drug hypersensitivity to methotrexate or acitretin, acute respiratory distress syndrome, sometimes due to a pulmonary capillary leak syndrome, is a rare cause of pneumonitis in the course of psoriasis, and may be fatal. Its pathogenesis is unknown. However, animal models suggest a role for T-helper (Th) 1 lymphocytes, known to be activated in psoriasis, and a role for tumour necrosis factor-alpha, a major Th1 cytokine, in alveolar damage.