Dermatology Quiz

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.

Generalised itching with wrist lesions

Fig 1. Excoriated lesions
Figure 1. Excoriated lesions on the patient’s wrists.

A man presents with a six-week history of intense generalised pruritus sparing his face that is worse at night.

Muscle weakness with knuckle erythema

Fig 1. Erythema
Figure 1. Dorsum of the patient’s hand showing erythema over the knuckles and interphalangeal joints.

A boy develops facial rash, periungual erythema and pruritic erythematous patches on his knuckles and interphalangeal joints. General malaise and proximal muscle weakness was also present.

Pearly papules on the thighs

Fig 1. Pearly papules
Figure 1. Pearly papular lesions and an inflamed lesion on the patient’s left thigh.

A boy has developed pearly, umbilicated, firm papules on his thighs.

Pigmented rash localised to the groins

Fig 1. Pigmented rash
Figure 1. Pigmented rash involving both groins and perineum.

A man presents with an irritable, pigmented rash confined to his groins and perineal area.

Tufted hairs wrapped in asbestos-like scale

Fig 1. Hair scale
Figure 1. Thick asbestos-like scale wrapped around tufts of scalp hair.

A woman presents with adherent asbestos-like scale bound around tufts of hair within her scalp.

Acral blisters with arthritis

Fig 1. Acral blisters
Figure 1. Acral blisters and erosions on the patient’s hand.

Over two months, a woman developed nonpruritic blisters and fragile skin on the dorsal surfaces of her hands. These developed after commencing naproxen for arthritis.

Tense blisters with IgA deposits

Fig 1. Blisters
Figure 1. Large blisters on the palm.

A woman, post cardiac surgery, develops large blisters from urticarial lesions on her palms and soles after receiving vancomycin and ciprofloxacin for a postsurgical wound infection.