Approximately 1/20 people have at least one hypopigmented macule. Patients may worry about the presence of pale patches and relate them to other diseases. Hypopigmentation can be disturbing, especially if it is visible. For people with darker skin, hypopigmentation can also pose a stigma. Most causes of hypopigmentation are not serious, they can be diagnosed clinically and be treatable, but in some cases referral to a specialist may be required.
What data from the history and physical examination should be taken into account?
♦ Demographics:
• Age: Pityriasis alba typically affects children ; Pityriasis versicolor usually affects young adults and vitiligo affects people of any age but commonly begins before age 30.
• Race – hypopigmented patches occur in all racial groups but are much more noticeable in those with darker skin; Post-inflammatory hypopigmentation ( which appears after the rash has resolved) is also more common in people with darker skin. Leprosy should be suspected in patients who reside in geographic areas where this disease is still common.
Ask the patient to describe how the pale spot started, how it has developed, and whether he or she has any other spots. Discuss the impact the condition is having on your self-esteem and wider aspects of your life.
The clinical examination will help determine:
• Distribution -pityriasis alba usually affects the head, neck, and arms; Pityriasis versicolor commonly affects the torso and vitiligo typically affects the face, genitals, hands and feet, and flexors. Remember that a solitary patch can be the start of more patches.
• Symmetry- pityriasis versicolor and vitiligo are usually symmetrical.
• Surface changes- The production of fine scales (which appear by scraping the skin with a scalpel) suggests pityriasis versicolor ; Pityriasis alba has an eczematous-looking surface.
• Evidence of another inflammatory skin disease- Coexistence with previous inflammatory eruptions (such as eczema or lupus) raises the possibility of post-inflammatory hypopigmentation.
What are the common causes of hypopigmentation?
♦ Vitiligo
Vitiligo Symmetric Depigmentation Patches
How is it presented?
This autoimmune condition causes chalky white skin patches, usually symmetrical. Early active patches may have less defined borders and may not have lost all pigmentation. Vitiligo affects up to 1% of the population. Its onset usually occurs gradually before the age of 30, but it can appear at any age and be rapid. There may be a family history of vitiligo or other autoimmune diseases such as thyroid disease or alopecia. In addition to decreased self-esteem, some patients may become socially ostracized and have difficulties with job opportunities and marriage prospects. The diagnosis is usually clinical.
What are the available treatments?
There is evidence from randomized controlled trials that some treatments work well and that early intervention can improve response to treatment. Small trials have shown that potent and ultrapotent topical corticosteroids applied once/day can achieve successful repigmentation, as can tacrolimus ointment 0.1%, applied twice/day for 6 months.
Advise patients to use high-factor sunscreen to prevent sunburn and reduce tanning of normal skin, which makes vitiligo more noticeable. Refer the patient to cosmetology services for masking makeup. Refer patients with rapid progression of vitiligo dissemination (few months) or who have not responded to 3 months of topical treatment. Patients with extensive vitiligo (>10% of the body surface area, equivalent to more than the area of the arm and hand) or with vitiligo in exposed sites that has not responded to other treatments may benefit from phototherapy.
What you need to know What do you need to know • In many cases, nonspecialists can do a diagnostic workup for hypopigmentation from the history and physical examination alone. • Common causes include vitiligo, postinflammatory hypopigmentation, pityriasis versicolor, pityriasis alba, and halo naevi. • Take time to understand how skin changes affect self-esteem, as well as work and home life. |
Post-inflammatory hypopigmentation
Post-inflammatory hypopigmentation after psoriasis treatment
How is it presented?
Pale spots may appear on the skin after any inflammation. such as discoid eczema, psoriasis, cutaneous lupus, sarcoidosis, thermal burns or cryotherapy. Patients with dark skin are particularly prone to this type of hypopigmentation or also hyperpigmentation.
How is it treated?
Postinflammatory hypopigmentation usually resolves spontaneously once the underlying condition has been successfully treated but may take several months.
Pityriasis versicolor
Slightly scaly hypopigmented patches on the trunk are typical of pityriasis versicolor
How is it presented?
This fungal infection, typically with Malassezia species , presents as a flat, scaly discoloration of the skin on the trunk and limbs, usually in young adults. It occurs more often in warm climates.
The diagnosis is usually clinical, but when the clinical signs are subtle, scraping the superficial skin for a mycological study (using a scalpel blade) can help confirm the diagnosis .
How is it treated?
In general, topical ketoconazole 2% (once/day for 5 days) is usually effective. An alternative is 2.5% selenium sulfide shampoo (1 time/day for 7 days).
Explain to the patient that changes in color of the affected skin can last many months after treatment and are sometimes permanent. Additional treatment is only necessary if the patches continue to flake when stretched or scratched.
Pityriasis alba
Slightly scaly patches of hypopigmentation on the face of a child with pityriasis alba.
How is it presented?
This mild, superficial eczema causes white scales (pityriasis (alba), typically on the cheeks, chin, and arms of up to 5% of children, with no difference in incidence between the two sexes. Patients often present with it after a sunny holiday, because the tanning of neighboring skin makes the pale patches more evident. The diagnosis is usually clinical. Skin scrapings for mycology will be negative.
How is it treated?
Pityriasis alba resolves spontaneously. Advise patients to regularly use emollients to improve dryness. A mild topical steroid (such as 1% hydrocortisone) will reduce inflammation.
Halo naevus (Sutton’s nevus)
Benign melanocytic nevus with surrounding hypopigmentation (halo naevus)
How is it presented?
Halo naevus occurs when a benign melanocytic nevus is destroyed by the immune system. The reasons for this are unknown. As the benign melanocytic nevus is destroyed, the melanocytes are damaged and a border of pale skin develops around it. Over a period of several months the original nevus disappears, leaving a hypopigmented macule, which gradually returns to its normal color over months or years. Halo naevi occurs in about 1% of children and young adults, and both sexes are affected equally. It commonly occurs in the summer when the tanning of the surrounding skin makes the halo more prominent.
Halo naevi can rarely be triggered by malignant melanoma located elsewhere on the body, so a thorough examination of the skin is important. On the other hand, some malignant melanomas can develop a halo around them, therefore, when in doubt about the diagnosis, referring the patient to a dermatologist should be considered. Patients with halo naevi do not require treatment, only monitoring. Advise sun protection since the naevi halo does not contain protective melanin and will burn easily.
Less common causes of hypopigmentation
| Condition | Main age group affected | Diagnostic features of pale patches | Patch distribution | Observations |
| Piebaldism | From birth | White tuft, narrow surrounding edge of dark skin | Face, trunk and extremities | This rare autosomal dominant disease can also be associated with deafness (Wandergurg Syndrome). |
| Progressive macular hypomelanosis | Young women | Multiple, poorly defined, circular on the trunk | Trunk | Uncertain cause although Propionobacterium may be involved. Acne treatment (tetracyclines) may be useful |
| Tuberculoid leprosy | Beginning in adolescence | Reduced sensation | Anywhere | Caused by Mycobacterium leprae, it continues to prevail in areas of Africa, Southeast Asia and Brazil. Refer to a specialist. |
| lichen sclerosus | Onset in middle age although it can occur earlier | Bright white, atrophic | Mainly genitals but can occur anywhere | Treatment with ultrapotent corticosteroids. |
| Idiopathic guttata hypomelanosis | From the middle ages | Very widespread, lower case | Arms and legs, especially the parts exposed to the sun | Unexplained aging process, No treatment available, covering makeup |
| Cutaneous T-cell lymphoma fungal mycosis | From middle age to old age | Multiple eczematous pale patches | Trunk and extremities | The hypopigmented variant is extremely rare but is an important differential diagnosis. If suspected, refer to a specialist. |
