I can't find any arguments against SJS, but let's try and see if there are arguments in favor of an alternate diagnosis. Of course the antecedent is imp. for ex. was there a hx of drug intake ? - then it would go in favor of SJS and only SJS in the pediatric age group. In an older age group, let's say 40 +, we have to think of Pemphigus vulgaris as an additional possibility ( a lot of drugs are being implicated for this adverse reaction ). The cornerstone of Mx in any condition, with excessive epidermal barrier loss is to manage the ensuing fluid and electrolyte loss and preventing bacterial infection esp. pseudomonas ( just like in a burn patient ). But in addition if p vulgaris is the underlying cause, then steroids are also central to Mx....so it is imp to ascertain the etiology. Steroids will help in the case of SJS as well, but the quantum of steroid Rx is smaller ( in terms of duration and dose ). Mucosal involvement is common and argues in favor of both SJS and P vulgaris Now is it possible to differentiate SJS from PV ? becos, on initial presentation the fully evolved lesions could look the same. Yes, the primary lesion holds the key. If primary lesion is not seen at presentation, then the patient can fill us in with that info. If the patient says, that it started as tender dusky red patches of erythema that turn dark red to brown black and then into a hemorrhagic erosion, then it goes in favor of SJS. But if the patient mentions about a flaccid bulla primarily (with or without preceding erythematous base ), then it goes in favor of Pemphigus vulgaris. Now let's come back to the pediatric age group and look at the possible differentials 1) Impetigo - infection caused by Staph or Strep that begins as a red macule that evolves in 24 hours into a vesicle and then into a pustulewhich then bursts to leave behind the very characteristic and pathognomic - yellow brown crusts with a 'stuck on appearance'. Gram staining will show -> gram + bact within neutrophils. A subset of patients with recurrent impetigo, may hav an underlying Ig deficiency...so do check for the levels if u suspect and consider penicillin prophylaxis. Recurrent impetigo cud also b the initial presentation in pediatric HIV. 2) Staphylococcal Scalded Skin Syndrome - easy to recognise since it looks like a sclad ( very superficial erosions that look like parchment membrane and don't have the characteristic crust of impetigo ). Also, the lesions don't contain neutrophils with bacteria camping within ( since it is an exotoxin mediated pathology ). 3) Staph or Step infection presenting as Steven Johnson Syndrome - yes, definitely possible but the vast majority of SJS cases are adverse drug reactions. 4) Erythema multiforme - a milder variant of SJS. We do have mucosal involvement, but hemorhagging is rare. *********************************************************** Now SJS has 2 siblings, the youngest and cutest of the three is - erythema multiforme. The eldest ( nasty and antisocial ) is - Toxic Epidermal Necrolysis. Just like all siblings they have similarities and differences. let's look at what those are.... Intro - the 3 entities probably represent morphological and distributional variants of the same pathologic process. Both drugs and infections can induce either of the three. Drugs - Sulfonamides, NSAIDS, tetracycline, penicillin, phenytoin, quinolones, rifampicin, INH etc. Infections - Viral ( Herpes simplex ), bacterial ( Streptococcal ), mycobacterial and mycoplasmal Closer look at Erythema Multiforme - as implied in the name, the lesions are multiform ( varied morphology ). Initial lesions are erythematous macules and patches that rapidly become elevated to form papules and plaques which develops a dark red center. Within a few days, the lesions progress to typical target lesions ( also called bull's eyelesion or iris lesion ) that comprise 3 concentric zones, from outside in, erythema ( bright red), edema( pale ) and the dark red center that represents either purpura or vesiculation. Erosions surrounded by erythema charecterise the mucosal affection. Distribution - mucocut. jxn ( lips, glans penis ), mucosae ( oral, conjunctival), acrae (palms, soles,, dorsa of hands and feet ) and extremities are preferentially involved. Trunk is affected commonly, though the density of the lesions is lesser. Steven Johnson syndrome is similar to erythema multiforme with the following differences. Etiology is similar, save for the fact that drugs are more commonly implicated. Skin lesions are similar but target lesions ae less common, bullae are commoner and lesions tend to be concentrated over mucosae and mucocutaneous junctions leading to severe mucosal erosions and hemorrhagic crusting. Constitutional disturbance is severe and systemic complications are commoner. Toxic Epidermal necrolysis - although etiopathologically related to reythema multiforme, toxic epidermal necrolysis is a life threatening disease due to necrosis of whole body epidermis and mucosal epithelia. Epidermis peels off in large sheets on a background of diffuse tender erythema and bullae all over the body. mucosal lesions resemble Stevens Johnson Syndrome. Nikolsky sign is positive. Systemic complications are fluid, electrolyte and temp. imbalance and propensity for developing infections. THerapy is similar to that of 100% superficial burns. ************************************************************************* Related Self Assesment Question A 24-year-old woman presents with a diffuse rash. She had "sores" of her mouth and eyes as well as numerous "spots" on her trunk. but now the rash has spread throughout her body. She is uncomfortable and her skin is warm and tender. Pressure applied to skin adjacent to the lesions seems to extend the lesion into the normal appearing skin. In exploring her recent history, which of the following is most likely? (A) She recently had a viral upper respiratory infection (URI). (B) She was being treated for a urinary tract infection. (C) Shehashumanimmunodefi.ciencyvirus (HIV). (D) She was recently diagnosed with leukemia. (E) She has gout. Answer B. The patient has toxic epidermal necrolysis (TEN), which is a vesiculobullous disease that is characterized by diffuse epidermal detachment. It is part of a continuum with Stevens-Johnson syndrome (SJS) and is diagnosed when the degree of epidermal detachment exceeds 30% of the body surface area (whereas SJS is diagnosed when epidermal detachment is < 10%). Drug exposure, particularly to sulfonamides, and to a lesser degree, anticonvulsants, is the most common cause of SJS and TEN. A recent urinary tract infection implies that this patient had been taking trimethoprim/sulfamethoxazole when she developed TEN.
