NURS 6531 integumentary case studies: planning guide

Each of the three cases is built around a specific wrong answer that the presentation invites, and the assignment's middle question is asking you to name the feature that rules it out.

The Forum asks for a primary diagnosis, three differentials, the role the history and physical examination played, and treatment options. That third element is where most posts go thin, because it is easy to write that the history and examination were important and hard to say which single finding moved the diagnosis. Every one of these cases contains one discriminating feature and at least one feature pointing confidently the wrong way. Identify both, and the post writes itself; identify neither, and you produce a description of the patient followed by a diagnosis that appears from nowhere. The stems are written this way deliberately, which is worth knowing before you read them: each detail is either load-bearing or bait, and very little is filler. Read each stem twice before deciding, once for the clinical picture and once asking what each specific detail was put there to do.

In the first case the distribution is the diagnosis. A pruritic eruption with tiny vesicles and scaling in the finger web spaces, on the wrists, around the belt line and on the feet and ankles, sparing the face and trunk, is a pattern rather than a rash — and the pattern is what separates it from the eczematous and contact differentials that would otherwise fit a scaly itchy rash. The recent hotel stays are the feature pointing the wrong way, because they invite bed bugs, and bed bug bites do not concentrate in web spaces. Itch that is worse at night, and the question of whether anyone in the household is also itching, are the two history items that most efficiently confirm the pattern. Both are questions the stem does not answer, which means naming them demonstrates you know what you would still need to ask rather than only what you were given.

The second case is the one where a criterion most students trust will actively mislead them. The lesion has an irregular border, uneven dark colour, a scaly surface and a two-year history of changing colour, in a fair-skinned outdoor worker with heavy adolescent ultraviolet exposure — and it is 0.2 cm across. Against the ABCDE mnemonic, the D for diameter greater than 6 mm is the single criterion this lesion fails, and it is the criterion most likely to be treated as decisive. It should not be. Depending on the series, somewhere between 2% and 38% of diagnosed melanomas measure under 6 mm, with around 30% found below that threshold. A criterion that would miss roughly a third of cases cannot carry a decision on its own, and treating it as though it can is how a small melanoma gets watched instead of biopsied.

The E for evolving is doing the work here, and there is evidence for treating it as the strongest of the five rather than the last one listed. In roughly 70% of early-detected melanomas the patient noticed the lesion changing before seeking care, the most commonly identified feature is a change in size, and focusing on change rather than on irregularity is more likely to identify melanoma early. So the defensible reading of this case is that four of five criteria are met, the fifth is the weakest, and the patient's own two-year observation of change is the strongest single piece of evidence in the stem. Saying that explicitly is a stronger post than reciting the mnemonic, because it shows you can weight criteria against one another rather than only check them off, which is the actual skill the case is testing.

The third case contains the sharpest clinical trap in the set, and it is not a diagnostic one. The patient has unilateral lesions on the right side of the face and neck, with itching plus tingling and pain, and she has arrived with a self-diagnosis and a specific request: a refill of triamcinolone 0.1%. Her eczema history is real and her occupational-exposure theory is plausible, which is exactly what makes it a trap. Unilateral distribution that respects a boundary, together with pain and tingling that accompany or precede the lesions, is not how eczema behaves, and prescribing the topical steroid she has asked for treats the wrong disease. The clinical lesson here is uncomfortable and worth stating: the patient has given you a coherent story, and the coherence is what makes it persuasive rather than what makes it correct.

Two things follow from that and both belong in the treatment section. If this is herpes zoster in a facial distribution, the ophthalmic division of the trigeminal nerve is a live concern — herpes zoster ophthalmicus accounts for something like 10% to 20% of zoster cases, and antiviral therapy is most effective at preventing ocular involvement when started within 72 hours of rash onset, with no data supporting efficacy after that window. That makes this a time-critical presentation rather than a routine one. Topical corticosteroids in this setting are not a substitute for antiviral therapy and should never be given without it, which is precisely what a refill would amount to. Writing that sentence in your treatment section -- naming what you would decline to prescribe and why -- is worth more than any number of correct choices, because it shows the request was recognised and refused rather than simply not considered.

For the treatment section generally, the assignment says potential treatment options based on your diagnosis, which is an invitation to specify rather than to name a drug class. Say what, at what strength, for how long, what the patient is told about contacts or household members where relevant, what follow-up interval, and what would make you escalate. For the pigmented lesion the answer is not a treatment at all but a procedure and a referral, and recognising that a biopsy decision is the intervention is itself part of the answer. For the pruritic rash the plan does not stop at the patient either, since simultaneous treatment of household members and close contacts is what prevents the reinfestation that otherwise brings them back in three weeks.

Three differentials are required alongside the primary, and they should be diagnoses that were genuinely in contention for this patient rather than a list of everything that causes a rash. For each, name the feature in the stem that argues against it. That is the same discipline the history-and-physical question is asking about, applied one differential at a time, and it converts a list into reasoning.

Name the discriminating feature, name the feature that misleads, and let the treatment section show you know which of these three cases cannot wait.