https://www.vetsurgeon.org/f/clinical-questions/29219/possible-differentials-for-chihuahua-puppy-with-papules Possible differentials? Sorry for the inexact history but the following is what I have to work with! Chihuahua female puppy. Presented as 12 weeks old but several adult premolars present. Microchip unregistered so cannot confirm age. O reports hasen-USTelligent Community 10https://www.vetsurgeon.org/thread/224224?ContentTypeID=1Tue, 14 Jul 2020 18:41:24 GMT146601cc-3922-4be7-9974-7e1d4e45a66b:1a517f87-c53b-4d16-99d2-ee072b31b9fbJudith Joyce<p>Definitely need cytology to narrow the differentials as David suggests, use a fresh pustule and aspirate to avoid contamination for best diagnostic yield if you can impression smear still valuable if you can&#39;t. . It is an unusual presentation for one so young but you doubt its age so I think drug eruption (its probably had drugs other than vaccine, not necessarily prescribed by you) and pemphigus group have to be on the list.</p> <p>Still need to rule out parasites - history is consistent with &nbsp;demodicosis even if an unusual presentation. This would be another reason to spare steroids. Couldn&#39;t rule out atypical scabies without skin scrapes and therapeutic trial.</p> <p>Think &#39;puppy head gland&#39; disease has to be on the list though it would be an unusual presentation. Is there lymphadenopathy?</p><div style="clear:both;"></div>https://www.vetsurgeon.org/thread/224219?ContentTypeID=1Tue, 14 Jul 2020 16:46:27 GMT146601cc-3922-4be7-9974-7e1d4e45a66b:e3805f89-fb3c-4b1e-80d6-e3c63ef15734David Bentley<p>The best thing to do is to try and do cytology on an aspirated pustule to see what exactly is going on. ? Neutrophils with intracellular cocci if pyoderma , neutrophils and acantholytic cells if pemphigus, eosinophils if very rare eosinophilic pustulosis ( though they quickly form collarettes). If there is a pyoderma. best not to give it steroids! Even if no pustules, scrape a papule and get an&nbsp; impression smear. It will tell you a lot, so at least you know what cell type is in predominance. ...e.g. eosinophils with parasites,&nbsp; &nbsp;then you can narrow down your list of differentials.&nbsp;</p><div style="clear:both;"></div>