Is it ever appropriate to use hydroxychloroquine temporarily in higher doses (more than 5mg/kg) to control lupus activity such as skin manifestations?  

The risk of retinal toxicity with long-term use of doses higher than 5mg/kg was shown by Melles and Marmor; PMID 25275721. There are reports of developing retinal toxicity even with short-term use of HCQ mostly coming from oncology literature (e.g. Navajas et al., PMID 26651304).There is some publis...