Dermatology Quiz

A painful violaceous lesion on the thigh

Figure. Violaceous lesion
Figure. The violaceous lesion at presentation.

A 48-year-old woman presents with a painful lesion on her thigh.

Sudden onset of blisters on the arms and neck

Fig 1. Arm rash
Figure 1. The patient’s rash at presentation.

A 56-year-old woman presents with sudden onset of a bilaterally symmetrical blistering eruption on her neck and forearms.

A tender rash on the legs

Fig. Leg rash
Figure. The patient’s rash at presentation.

A 14-year-old boy presents with a slightly tender rash on both lower legs a week after an attack of tonsillitis. He had been previously well.

An enlarging lesion on the neck

Figure 1. The lesion occurring on the patient’s neck, which has recently enlarged and become more prominent.

A 13-year-old boy presented with a raised, hyperkeratotic, warty lesion on his neck.

Recurrent itchy papules in a 12-year-old boy

Fig 1. Itchy papules
Figure 1. The itchy papular rash on the patient’s hands and knees. The rest of the skin is normal.

A 12-year-old boy has developed itchy papules on the palms, soles, elbows and knees each spring for the last three years.

Sudden onset of blistering lesions in a young boy

Fig 1a. Arm lesions
Figure 1a. Blistering lesions on the patient’s arm.

A 12-year-old boy presents with sudden onset of blistering lesions on his arms and legs, occurring a few days after he developed a typical cold sore on his upper lip.

Asymptomatic annular lesions on the hand

Fig 1. Annular lesions
Figure 1. Asymptomatic annular lesions on the dorsum of the patient’s hand.

A 35-year-old man has two asymptomatic, annular lesions on the dorsum of his left hand, which have slowly expanded over the past three months.

Lifelong irregular pale patches

Fig 1. Hypopigmented patches
Figure. Multiple irregular hypopigmented patches contrasting with surrounding erythema over the shoulder and back.

A man presents with a lifelong history of asymptomatic irregular pale patches outlined by a pink blush localised to his shoulder and back. These failed to react to dermographism. What is the differential diagnosis?

A blistering eruption in pregnancy

Fig 1. Symmetrical rash
Figure 1. A pregnant woman with a generalised symmetrical rash of blisters and serous crusts distributed in an annular configuration.

A pregnant woman presents with a generalised symmetrical rash of blisters and serous crusts that flared in the third trimester.

Reticulate pigmentation of axillae

Fig 1. Reticular pigmentation
Figure 1. Reticular pigmentation and papules on the axilla.

A woman presents with a 10-year history of asymptomatic mottled reticulate pigmentation localised to her axillae and groins. Her mother and sister were similarly affected.