I had a dermatology spot-diagnosis exam a couple of days ago. It’s taken at the end of the dermatology round. There were 5 live cases, which were to be diagnosed or described (according to the question). The second part they required was mostly the treatment, and sometimes the investigations needed. We stand by each case for one minute. We write down the answers on a given paper.

The cases were:

1. Impetigo

The patient was a young girl, around 4 to 6 years old, who had around 10 pustules, some of them crusted, around her mouth. At first I thought it was chicken pox, being very common at this age. I uncovered her belly and chest, but there were no lesions. I asked her mother, who was right beside her, if the girl had had fever before the rash appeared, but she denied that. I asked her when it appeared, and she said it appeared two days ago. I thought, “may be it’s a very early chicken pox manifestation?”. But that’s wrong.

Fact: Chicken pox lesions appear on the face and the trunk at the same time. No lesions on the trunk excludes the diagnosis of Chicken pox.

The treatment would be topical staph.-sensitive antibiotics (ABs) like mupirocin. In case of resistance, oral ABs covering staph. and step. organisms should be given.

2. Psoriasis

A man in his forties had numerous erythematous plaques of different sizes on the extensor surfaces of his arms and legs. They were also found on his scalp and face. There were no silvery scales found.

Topical steroids would do no good to that patient because the disease is extensive. PUVA should be considered, in addition to other aggressive agents as methotrexate and immunomodulatory drugs.

3. Tinea Versicolor

On the upper back of a man in his twenties numerous hypopigmented macules were found. The macules were variably-sized and tended to coalesce.

Since the disease is localized, the patient may apply topical antifungals like any imidazole derivative drug (e.g. ketoconazole, itraconazole,..etc). Selenium sulfide lotion may be used as well. Investigations include KOH testing (spaghetti and meatballs appearance) and Wood lamp test (positive fluorescence) on the scraps.

4. Chicken Pox

Many centripetal vesicles, pustules, and crustations were found on the face and the trunk of a young child. The diagnosis was definite, especially that the attending mother mentioned that the boy had had fever prior to the onset of the rash. This case made me re-evaluate my diagnosis of the first case because they wouldn’t have cases with the same disease in the exam, so I just switched case numbers, and I was good to go!

Chicken pox is usually left untreated in children because it’s self-limited. Symptomatic therapy is the mainstay management.

5. Acne Vulgaris

That was a typical presentation of the disease on the face of a teen girl. The disease was mild, consisting only of white comedones, and a few inflammatory nodules. No pustules nor cysts were found.

The treatment would be topical ABs (like clindamycin) and topical benzoyl peroxide.