methyldichloroarsine
... that the symptoms of exposure to the blister agent methyldichloroarsine clinically resemble poison ivy?
... that the symptoms of exposure to the <a href="./Blister_agent" id="mwC08" rel="mw:WikiLink" title="Blister agent">blister agent</a> <b id="mwC1A"><a href="./Methyldichloroarsine" id="mwC1E" rel="mw:WikiLink" title="Methyldichloroarsine">methyldichloroarsine</a></b> clinically resemble <a href="./Poison_ivy" id="mwC1I" rel="mw:WikiLink" title="Poison ivy">poison ivy</a>?