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Post by Irene Lawrence on Nov 19, 2008 20:03:33 GMT
Hi all. Looking for some advice about silver nitrate and its application/follow up. I have a patient with a large VP that he has had for over 2 years. It is located on his 5th met head and has recently become very painful. I usually take the line of not treating VPs but as this is causing pain, I have agreed to try and help - with a strict no promises guarantee! I have tried using occlusal but have not had much success. If I use silver nitrate after debriding the VP, what is the expected length of time between treatments and is there a limit on the number of times that silver nitrate can be used on the same VP? Many thanks, Irene
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Post by hurleygirly on Dec 1, 2008 19:52:17 GMT
Hi all, I am really interested to hear your views on this... So far I have tried 3 applications, 2 days apart (although I think 24 hrs is the minimum?), with an assessment 2 wks later. This has been reasonably successful...but is the max number of treatments 6?  |
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Post by robertisaacs on Dec 1, 2008 20:51:09 GMT
Its a while since I did pharmacology but i'll give it a shot. Silver nitrate is not a caustic in the truest sense, but rather is a protein precipitant. That is, it reacts with the protein in cells. A caustic will continue to act until all its reducing or oxidising capability is exhausted, or until it reaches low enough concentration to be ineffective. Silver nitrate is self limiting in its effect. I should be considered as a very different treatments to the other acids and alkali bases used. When its applied it instantly forms a white layer of this precipitant. This blocks further access of the chemical through the skin making the effect self limiting. The top layer then forms a blackened plaque of silver chloride which will self avulse in time. In the event that it is applied to broken skin it stings like a Bee hatch. To be honest i consider it a bit of a limp treatment for VPs. If you want to start on the theraputic ladder this is probably the first step. Vigerous debridement followed by Silver nitrate repeated every few weeks has been known to work. But unless the patient is high risk i would bypass this and go to a low concentration salacylic or similar. But Bel is the demaguru. I'm sure she'll be along in a minute.  Regards Robert |
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Post by chifhpod on Dec 2, 2008 10:09:47 GMT
Robert said "i consider it a bit of a limp treatment for VPs" and I agree. So its really only good for tiny VPs and leftover bits. Because of its self-limiting properties it will only penetrate about 0.5 millimeter. On a small VP, avulsion (loss of 'eshar' - fancy name for chemical 'scab') will occur in approximately 7 days. Larger areas take longer to fall off. When the black spot goes missing it is replaced immediately to kill/remove the next 0.5 mm. Wetting the skin (just damping with a water-wetted swab) is essential to dissolve the silver nitrate off the applicator and onto the skin. Where silver nitrate is used for removal of VPs, nothing less than the 95% caustic pencil should be emplyed. Old fashioned, works, predicatable, good for youngsters (because it needs no covering dressing and does not need to be kept dry). Contraindications: PAD, poorly controlled diabetics, advanced neuropathies. Do I get the No-Bel prize for this? |
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Post by blinda on Dec 2, 2008 13:02:03 GMT
I couldn`t put it better than Robert, so I won`t. It is true that although silver nitrate is often classified as a caustic (because it is caustic when applied to mucous membrane) it is really a very strong astringent. As the eschar toughens up the epidermal tissue it makes reduction easier with the scalpel on the return visit. It is a chemical aid to minute dissection and forms no other useful function for VPs. Manufactures recommendation for application for each VP should be for 1-2 minutes after reduction of keratinized tissue. Four further applications may be applied. Leave 24 hours between each application. You should be aware though, that continued use to an open wound can lead to argyria, which is a bluish-black discolouration of the skin due to depositions of granules of silver compounds in the connective tissue, which takes a long time to disappear and can cause further complications. It has been suggested that it has a mild keratolytic action but, as already highlighted, this mode is insignificant in comparison to the other acidic caustics. When looking at the research evidence and the number of complications that arise from the treatment of VP, sal acid (up to 60%) is suggested as an appropriate choice (Gibbs et al 2005). If you are not skilled in the use of strong caustics, where a cumulative effect could cause excessive tissue destruction, you should consider using a lower strength sal acid, e.g. in plaster form (12.5%), or refer to practitioner with training in cryosurgery/electrosurgery/low-level laser therapy. Some dermatologists are using Canthradin (Poison from the Chinese blister beetle) with very good results. However, it is only licensed for use in podiatry in the states and Canada and NOT by podiatrists in the UK. As I`m sure you are aware, the aim of all treatments is to create a controlled auto immune response which stimulates the body's immune system to recognise the virus & destroy it. The length of treatment will vary according to the resistance of the verruca. Some may be successfully treated in a relatively short time, but others can take several weeks or months to resolve. If the VP has been around for more than 2 years, and is painful, I would suggest more aggressive treatment by an experienced practitioner. I agree with chifhpod, that Silver nitrate may well be effective on healthy children, due to the placebo effect, similar to buying the VP. However, you should apply a dressing after application until it has dried as the silver nitrate stains EVERYTHING! Many insurance claims made against pods have been due to spillages/stains from chemicals on carpets and furniture  ! Cheers, Bel Gibbs S, Harvey I, Sterling J, Stark R. Local treatments for cutaneous warts (Cochrane review, 2005) Oxford. |
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Post by chifhpod on Dec 2, 2008 14:22:12 GMT
Hi Blinda, No way intended to reduce the thrust of your post, but I feel the need to add to one or two of the points you made. Silver nitrate deos not attempt to stimulate the immune system. The creation of an eshar binds the VP surface which becomes stiff and separates from the skin surface bringing a layer of VP infected tissue with it. This is a purely physical effect. The length of treatment is more exactly a function of the rate of growth of the verruca (itself a reflection of the immune status of the patient). It is not intended as a placebo, but is used to physically reduce tissue - kill a layer/ lose that layer/kill the next layer. It is advocated for use in young children because once applied it cannot be taken away. Silver nitrate reacts immediately on application with proteins in the skin. As Robert pointed out, the layer so-formed prevents its deeper penetration, so argyria is highly unlikely given the quantities and duration for which we shall use it. I must also disagree that a dressing is necessary. So long as the application is completely dry before the socks are put on there will be no transfer or loss of the chemical onto the socks (no staining). The patient could be advised to wear black socks if you are still worried. Part of its value is that it does not require a dressing that must be kept on and must not be allowed to move upon the skin surface, as is the requirement with salicylic acid. It means a child can run and play without restriction. I fully agree that 60% salicylic acid is the treatment of choice, so long as that is appropriate to the patient. A 7 day application of 60% sal acid will penetrate 0.5 cms (ten times as deep), meaning that progress through a lesion can be much more rapid where sal acid is employed. Sal Acid is again a keratolytic and its use is again to physically make possible the reduction of an infected cell mass - nothing whatever to do with immune systems or immune response. Kill tissue/remove tissue/ kill next layer of tissue, again a physical process. Spontaneous resolution will occur if the immune system gets to grips with the virus. Spontaneous resolution may occur during the course of our treatment. The resolution is unlikely to be brought about by our treatment. We usually begin treatment precisely because the immune system has not acted. Intended to help  hpchifhpod |
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Post by robertisaacs on Dec 2, 2008 14:39:22 GMT
Again i stick my toe into the unfamilier waters of dermatology.
I would disagree here. My flawed and out of date understanding is that VPs are intradermal and therefore "off radar" for the immune system in usual means. When the virus is detected (and i understand there is an element of chance as to when this takes place) a cascade is initiated which ultimately results in the immune system destroying the virus within the tissues.
By causing insult to the tissue, by aggressive debridement, caustics, or cryotherapy we create an inflammatory reaction. This involves an increase in superficial circulation growth factors and an increase in the concentration of white cells in the area which increases the odds of the immune system "seeing" the virus. The greater the insult to the tissue, the better the chance of success.
Removal of infected tissue may well cause a reduction in pain but i cannot see how it could cause resolution of the lesion unless by radical debridement. I cannot see how it could remove every single viral body.
To return to the commonplace and everyday it should be noted re this point
That some vp / corn plasters have 40% sal acid! Obviously the ingrediant of the specific preparation should be checked. I have seen (and indeed purchased) up to 50% sal acid OTC so its not hard to get hold of.
I'd be interested in peoples protocols for sal acid. I tend to use 60 or 75% paste with a few monochloracetic acid crystals embedded in it, masked and left on for 4 - 7 days, then returned and repeated 3-4 weeks post treatment. What do others do?
Regards
Robert
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Post by chifhpod on Dec 2, 2008 15:44:39 GMT
Sorry Robert - put 'em up!
This was practised as 'file and bleed' a few years ago. The theory that trauma would draw the attention of the immune system to an HPV infection has long been discredited, having failed to produce any recordable results, and has now been abandoned.
A keratolytic - ANY keratolytic - seeks to remove tissue (kerato =skin, lysis = breakdown)
Salicylic acid and silver nitrate are both keratolytics - no difference in this respect. Their mode of action differs, but only in respect of how they prepare a surface prior to its being lost/removed. (same difference).
Further to Bel's last post (I hope it won't be), taking a scalpel to a silver nitrate eschar should never be necessary. In my (long) experience, the eschar makes it difficult to remove a skin layer without unnecessary wounding. Also seems unnecessary since it is doomed to fall off anyway.
Not exactly looking for an argument, but here if you want one!! ;D
Cheers!
chifhpod
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Post by robertisaacs on Dec 2, 2008 17:25:46 GMT
Don't be sorry! Its when i have most fun!  Let us sift together for the gems of truth amid the mud of hearsay, the slime of "what i vaguely remember from college" and the wriggly squirmy things of "stuff that just makes sense does'nt it". Thats a big statement! In fact, if you have a minute, its a huge vast gargantuan rick waller of a statement with extra supports for its outlying areas, an advertising campaign and a huge neon sign above it flashing "THIS IS A BIG STATEMENT". As i said, my derma knowledge is second to just about everybody but i thought this was accepted canon! 1. Who discredited it? How? Why was i not informed 2. Has it been replaced by anything? 3. If so, what are the recordable results for that? 4. If this is not the modus for caustics, cryo, debridement LLLT (no trauma just growth factors) etc what is? And what is the common element? 5. Who has abandoned it? And in favour of what? Keratolytics break down keratin as you say. But i thought only the top two layers (statum spiyosaurus? spinyosum? something spiny.) have keratin. VP viral tissue affects all 4 layers does it not? I'm pretty sure i remember reading that it can affect down to the germinal cells and definitly the granny o layer. If their mode is purely keratolytic how can they affect the virus in the layers which contain no keratinocyts? Lets go to the phones... Robert Feeling whimsicle today. And more dyscslinkyslik than usual |
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Post by blinda on Dec 2, 2008 17:33:25 GMT
Hello again, Absolutely agree here, I`m sorry if I gave the wrong impression. Silver nitrate itself probably does not create enough of a controlled inflammatory response to stimulate the immune system (which is why I don`t use it for VPs on adults). I`m afraid I can`t agree with you here. Current thought is that VPs sit in the stratum spinosum ie, Roberts` “under the radar”, nowhere near the keratin layer which is where the eshar binds, so regular reduction would have no effect on the virus. The overlying callus is a physiologial protection which is formed to reduce peak forces and the only advantage of regular reduction is to make the patient feel comfortable, if it on a weight bearing part of the foot. If there is severe discomfort immediately after application of silver nitrate, it can be neutralized with saline water as it is an ion solution. As I said earlier, I agree that the action on the skin is to precipitation of protein, which in the presence of light turns brown/black. I find that this adheres so that skin striations/demarcated area in the callused epidermal tissue can be reduced easier with the scalpel on children and the visual aid of the eshar contributes to the placebo effect, IMHO . It is true that argyria is unlikely, as it is more often associated with colloidal silver solutions than with silver nitrate . However, it is recorded on the practitioner advice slip as a risk so should still be considered. Disagree if you must, but silver nitrate does not dry immediately. There have been insurance claims for this very reason. I like the black sock idea, but really, how many patients turn up for VP treatment with an array of coloured socks to choose from ? Silver nitrate does not require the same type of dressing as you would use for sal acid, (a small strip of fleecy web will suffice, just until it has dried – can still run and play  . As you quite rightly pointed out, they work by different modes of action as the sal acid penetrates deeper and has more chance of creating an inflammatory response. This is why the Cochrane review suggests that 60% sal acid is appropriate tx. (Then again, it also infers you might as well use a placebo  ). Could it be: OR, I have to agree with Robert on this one. The keratolytic value of sal acid is two fold. It is a form of aggressive debridement of callused tissue, so brings pressure relief and it creates a deeper controlled inflammation, which in turn increases those white blood cells to the area, which increase the opportunity for an effective immune response. It is true that there is scarce evidence out there to support this (Mainly due to the difficulty in research methods involved with VP tx). However, most practitioners will agree that the body has to made aware of the viral infection, which is sometimes brought about by aggressive tx. Agree 100% Good to have a debate about something other than biomech . Also valid point made re percentage of sal acid in plasters….always tell pt to check. Personally I use 60% paste (without crystals, cos I`m a coward ) masked and offloaded for one week, repeated again in 4 weeks. If no sign of improvement, I refer to dermatologist who has license (and insurance) to use more potent therapy. Then again you could try rubbing raw meat on it, bury the meat in my garden, etc, but I find it too cold at this time of year to dance naked around it at midnight. Cheers, Bel |
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Post by davidsmith on Dec 2, 2008 18:41:06 GMT
Hi all Here's some up to date references Warts Plantar 2007 Jeffrey S Cooper, MD, Clinical Assistant Professor, Department of Surgery, Medical University of Ohio School of Medicine; Consulting Staff, Department of Emergency Medicine, Mercy Children's Hospital www.emedicine.com/EMERG/topic641.htmRole of Tissue-Type Plasminogen Activator in Salicylic Acid–Induced Sloughing of Human Corn Tissue Ghanshyam D. Heda, PhD* Lee K. Roberts, PhD† JAPMA 2008 www.japmaonline.org/cgi/content/abstract/98/5/345I have a copy if you would like to read it. An Armamentarium of Wart Treatments Michelle M. Lipke, MPAS, PA-C Clinical Medicine & Research Volume 4, Number 4: 273-293 ©2006 www.pubmedcentral.nih.gov/picrender.fcgi?artid=1764803&blobtype=pdfDave |
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Post by chifhpod on Dec 2, 2008 19:36:09 GMT
Hi Robert/Blinda, I don’t need a canon to make a point! Big statement it may be, but the truth IS often writ large. The idea that induced inflammation produced reaction from the immune system died a quiet, natural death. It passed without ceremony and was scattered on the grounds of no grounds. I have observed over a working lifetime that things that work are generally put to use - things that don’t work get lost in the sands of time. It’s hardly worth writing up that something doesn’t work, is it? A bit like good news - not exactly ‘sexy’ and nobody wants to read it. Silver nitrate is most likely to be limited to the superficial layers of the epidermis, and we all seem to agree that this is due to the reaction with skin proteins and the formation of a limiting layer. So silver nitrate is shallow in its action. I think we might all agree to this much? But if we take off the stratum corneum and lucidum (there are 5 layers in the epidermis of palms and plantar surfaces), we can do it again a week later, week on week. Does the silver nitrate really care which layer it sits on? Salicylic acid 60% paste penetrates much deeper. By personal observation I have seen that it does not penetrate into the dermis, but certainly breaks down (kills) skin right down to the depth of the dermis. This is postulated (by me with a lifetime of empirical (and therefore of value) experience) to be due to the blood supply present in the dermis and absent from the epidermis. Does the salicylic acid really care which layer it sits on? I observe with the eyes of a trained observer that no inflammation whatever is caused by these applications. The skin with the virus-infected lesion is white, dead, macerated by application of the paste (seven days about). No inflammation above, below, around or imagined! Certainly nothing that could possibly get the immune system excited! A sort of absolute, flat, totally predictable and completely uneventful non-happening really, total entropy! What each of these preparations does do is to assist with physical removal, silver nitrate by creation of an eshar which will fall off in its own good time (average 7 days), and salicylic acid which destroys nerve endings and macerates the tissue it has killed. Live tissue would resist such maceration. Scoop it out with the verruca tissue embedded. Highly satisfying! LLLT (low level laser therapy employs red (ruby) light for its photobiological effects. It is said that the light produced at this wavelength stimulates cell division. Rather a red (ruby)-herring in this discussion, don’t you think? An afterthought…if inflammation wakes up the immune system, why do we not apply rubrefacient preparations to verrucae? Because inflammation does not wake up the immune system! ; ;D |
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Post by robertisaacs on Dec 2, 2008 21:47:57 GMT
Hey Chifhpod Canon. Not A canon ;D With respect, so says you. But saying it don't make it so! You beleive this and have reasons for beleiving so. However for an idea to die people have to stop beleiving it. And they have'nt! Thats not proof its right but is certainly proof that the idea has not died as you describe. You are the first person i have met who does not subscribe to this view. On the contrary! From Bad science.com People often publish pieces on problems with models and research. THe explosion of such a widespread view as this would surely be worthy of publication! Only if it is a pure keratolytic. Cos then it cares if the layers have keratin. But if it is an astringent as well as bel suggests it is entirely appropriate that it would function in lower layers. I rarely use Sal acid on its own, as i say i tend to use it with monochlor as well. But i have very certainly seen inflamation with that! And we know that the mechanism of mechanical trauma (such as might be caused by debridement to bleeding point) WILL cause inflamation. Monocytes and cytokines and the like. Even your experianced eye cannot detect interleukin concentrations! Depends on which probe you use. THe 820nm probe is blue light (if memory serves). As for being a red herring... well there is some evidence it works. Not the highest quality but then there is very little of the highest quality for anything! And if it works by stimulating growth factors Good question! Somebody should try it! That would certainly be evidence to support your case! So far as i can see the basis for your view that the mode of action for Cryo, caustics etc is not immunostimulation is that you cannot see inflammation with silver nitrate or with sal acid. Is there other evidence or opinion you can produce which supports your view? Because if not it is simply that. Your view. Does'nt make it wrong, but to suggest that it is the only valid view appears specious to me. This is fundamentally untrue. Inflammation DOES stimulate the immune system! This is odd. Its not biomechanics, yet i'm enjoying it immensely! And to you... Robert |
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Post by blinda on Dec 2, 2008 22:37:36 GMT
Yes please
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Post by blinda on Dec 2, 2008 22:52:45 GMT
Good innit ;D Perhaps we could now have a dedication derm section on the forum? I will have a read through the articles Dave posted and some others i have back in my surgery tomorrow. Interesting thoughts to say the least! Cheers guys Bel |
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hpchifhpod
Let us sift together for the gems of truth amid the mud of hearsay, the slime of "what i vaguely remember from college" and the wriggly squirmy things of "stuff that just makes sense does'nt it". 
. As you quite rightly pointed out, they work by different modes of action as the sal acid penetrates deeper and has more chance of creating an inflammatory response. This is why the Cochrane review suggests that 60% sal acid is appropriate tx. (Then again, it also infers you might as well use a placebo 
).