Common conditions that may cause patchy hair loss may be classified into two: one, the irreversible scarring type of alopecia where the skin is damaged beyond recovery; and, two, the reversible non-scarring type of spotty hair loss, where the skin is normal or only temporarily inflamed.
Causes of Non-scarring Type of Reversible Patchy Hair Loss
In non scarring types of patchy hair loss, re-growth of hair is the rule when the underlying cause is removed and early proper treatment is instituted. The most salient differentiating feature between the scarring and non scarring alopecia is the presence of hair follicle openings on the skin surface in the latter. A number of skin and hair diseases can cause this type of reversible, non-scarring patchy loss of hair:
- Alopecia areata. Alopecia areata is a localized, often recurrent, patchy hair loss of autoimmune origin where the body produces antibodies which attack and destroy the hair follicles. The bald patches in alopecia areata are smooth, with normal appearing skin and non-obliterated hair openings on the surface.
- Tinea capitis. Ringworm infection of the scalp is common among children before puberty. The patchy area shows scaling, broken hairs and crusts. The affected hairs are easily pulled out. In the black dot variety of ringworm, broken hairs at the surface are seen as black dots. In contrast to alopecia areata, intense itching is common in tinea capitis.
- Trichotillomania. Compulsive pulling and constant rubbing and twisting of hair tufts can cause patchy hair loss, especially on the sides of the scalp, eyebrows and eyelashes. Trichotillomania may be associated with psychiatric problems including obsessive compulsive disorder and psychosis. The bald patches are asymmetrical and uneven; presence of broken hairs of varying lengths is diagnostic of trichotillomania. Skin in the partially bald patch is usually normal, though abrasions and crusts caused by constant scratching and picking are also evident in the patches.
- Early patches of scarring hair loss may resemble alopecia areata.
- Traction alopecia. Tight braids, clips, hair weaving etc can cause direct pulling on the hair roots. In addition to the mechanical tear to the hair shaft, this can also cause loss of blood and nerve supply to the hair roots culminating in diffuse hair shedding in the area. Scalp margins and front of the scalp are usually affected in traction alopecia
- Secondary syphilis. A moth eaten patchy hair loss resembling alopecia areata is a typical feature in some cases of secondary stage of syphilis. Hence, screening tests for syphilis is mandatory in atypical looking spotty bald patches.
- Androgenic alopecia. At times the loss of hair in male and female pattern hair loss, especially in the vertex, may resemble the patchy hair loss of alopecia areata. The typical sites and presence of fine, vellus hairs within the patches should rule out alopecia areata.
How to Find Out the Cause of Reversible Patchy Hair Loss
Dermatologists and physicians trained in skin and hair disorders can make a correct diagnosis from clinical appearance of the bald patches on the scalp and other hair bearing areas.
Routine investigations are not needed in first incidence alopecia areata. If the diagnosis is in doubt, the following laboratory tests may be ordered by your dermatologist:
- Potassium hydroxide preparation to confirm/rule out fungal infections
- Blood tests for syphilis and systemic lupus erythematosus
- Thyroid function tests
- Complete blood count to rule out anemia or signs of generalized infections or blood disorders
- Finally, a biopsy of the involved skin may be necessary in cases where a definite diagnosis could not be arrived at even after clinical examination and routine laboratory investigations.
How to Treat Reversible Patchy Hair Loss
Pinpointing the exact cause of the hair loss is, of course, the first step in choosing the optimum treatment for reversible patchy hair loss due to any cause.
- Is it necessary to treat all cases of hair loss in alopecia areata? Most dermatologists are of the opinion that first instance alopecia areata with a limited number of small patches do not require any treatment as spontaneous hair growth is very common in alopecia areata. When the hair loss is extensive and recurrent, a detailed physical, psychological and laboratory work out becomes mandatory to find out the exact cause for the patchy hair loss in alopecia areata.
- Avoiding the environmental triggers coupled with effective treatments will ensure hair growth in majority of patients with alopecia areata. Injection of diluted strengths of corticosteroids into the bald patches is the most effective treatment for alopecia areata. Proper dilution and injection techniques are necessary for best results. Topical application of Minoxidil 2-5%, potent topical steroids, counter irritants like DNCB etc are some of the other alternatives for treating alopecia areata.
- Treatment of ringworm infection of the scalp requires a combination of systemic and topical antifungal medications and shampoos. A minimum treatment period of 3 months may be required for complete cure and avoidance of recurrence later on.
- Trichotillomania is best managed through psychoanalysis, counseling and, if necessary, a psychiatry referral.
- Secondary syphilis should be treated with proper doses of Penicillin injections and followed up regularly till complete serological cure. Contacts should also be investigated, and treated if necessary, in such cases.
- Traction alopecia needs patient education on hair styling.
Loss of hair in patches can create much anxiety in individuals. The accompanying fear of total loss of hair does not help either. From the above discussion, it is should be evident that most of the cases of reversible patchy hair loss are treatable conditions. Proper early diagnosis and appropriate therapeutic measures will bring relief to majority of patients with localised alopecia.
At the same time, it is also necessary to rule out the irreversible causes of scarring type of hair loss in patients with patchy alopecia.
Further Reading
- How to Get Rid of the Patchy Hair Loss in Alopecia Areata?
- Hair Loss Causes
- Treatment of Alopecia areata: National Alopecia Areata Foundation
References
- Ralf P, Elis AO, Andrew GM. Hair Growth Disorders, in Fitzpatrick’s Dermatology in General Medicine., 7th Ed, 1: 753-777, 2008
- Messenger AG et al. Disorders of Hair, in Rook’s Text Book of Dermatology, 8th Ed, 4: 66.1-66.100, 2010
- Klaus W, Richard AJ. Skin Signs of Hair, Nail, and Mucosal Disorders, in Fitzpatrick’s Color Atlas & Synopsis of Clinical Dermatology, Sixth Ed, 961-1067, 2009.
Disclaimer
The information given in this article is for educational purpose only so that patients are aware of the options available. No diagnosis should be made or treatment undertaken without first consulting your doctor. If you do so, the author or suite101 will not be responsible for any consequences. The images provided are for illustration purpose only.
Hanish Babu - Dr.Hanish Babu, MD is a dermatologist and a feature writer on Suite101.com with more than 200 articles related to skin diseases on the ...
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